MX2008009447A - Lost circulation compositions and methods of using them - Google Patents

Abstract

A lost circulation composition for use in a wellbore comprising a crosslinkable polymer system and a filler. The invention also relates to a method of servicing a wellbore in contact with a subterranean formation, comprising:placing a wellbore servicing fluid comprising a crosslinkable polymer system and a filler into a lost circulation zone within the wellbore. The invention also relates to a method of blocking the flow of fluid through a lost circulation zone in a subterranean formation comprising placing a first composition comprising a packing agent into the lost circulation zone, placing a second composition comprising a crosslinkable polymer system and a filler into the lost circulation zone, and allowing the compositions to set into place.

Description

LOST CIRCULATION COMPOSITIONS AND METHODS FOR USING THEM FIELD OF THE INVENTION This description relates to compositions for operating a sounding that experiences lost circulation. More specifically, this description is related to introducing compositions in a sounding when penetrating an underground deposit to reduce the loss of fluid in the deposit.

BACKGROUND OF THE INVENTION A natural resource such as oil or gas that resides in an underground reservoir can be recovered by drilling a borehole in the well. The underground deposit is generally isolated from other deposits using a technique known as well cementation. In particular, a borehole is typically drilled to the underground reservoir while a drilling fluid is circulated through the borehole. After the drilling is completed, a column of pipe, for example, casing, is put into the borehole. The primary cementation is then commonly done so that a cement slurry is pumped through the pipe column and into the annular zone between the pipe column and the walls of the sounding to allow the cement slurry to settle into a waterproof cement column and thereby seal the annular zone. Subsequent secondary cementing operations, that is, any cementing operation after the primary cementing operation, can also be performed. An example of a secondary cementing operation is compression cementing whereby a cement slurry is put under pressure to the areas of integrity lost in the annular zone to close those areas. Subsequently, the oil or gas that resides in the underground reservoir can be recovered by driving the fluid into the well using, for example, a pressure gradient that exists between the reservoir and the borehole, the gravity resistance, the fluid displacement using a pump or the resistance of another fluid injected into the well or an adjacent well. The production of fluid in the reservoir can be increased by hydraulically fracturing the reservoir. That is, a viscous fracture fluid can be pumped up the casing to the reservoir at a sufficient rate and pressure to form fractures that extend into the reservoir, providing additional trajectories through which the oil or gas can flow toward the reservoir. the hole. Unfortunately, it can be produced eventually water instead of oil or gas through the deposit through fractures in it. To provide more oil or gas production, a fracture fluid can be pumped back into the reservoir to form additional fractures therein. However, previously used fractures must first be clogged to prevent the loss of fracture fluid in the reservoir through these fractures. In addition to the fracture fluid, other fluids used to operate a well can also be lost in the underground reservoir while the fluids circulate in the well. In particular, fluids can enter the underground reservoir through depleted zones, areas of relatively low pressure, areas of lost circulation that have natural fractures, weak zones that have exceeded their fracture gradients by hydrostatic pressure of the drilling fluid, etc. As a result, it is more difficult to achieve an operation provided by such fluid. For example, a drilling fluid may be lost in the reservoir, resulting in the circulation of fluid in the borehole being too low to allow additional drilling of the borehole. Also, a secondary cement / sealant composition may be lost in the reservoir as it is being placed in the borehole, therefore returning inefficient the secondary operation to maintain the isolation of the deposit. Accordingly, there is a continuing need for compositions and methods to block fluid flow through areas of circulation lost in underground reservoirs.

SUMMARY OF THE INVENTION According to one aspect of the invention, a lost circulation composition is provided for use in a survey comprising a crosslinkable polymer system and a filler. According to another aspect of the invention, there is provided a method for operating a sounding in contact with an underground reservoir, comprising: placing a sounding operating fluid comprising a crosslinkable polymer system and a load in a lost circulation zone inside the sounding According to another aspect of the invention, there is provided a method for blocking the flow of fluid through a circulation zone lost in an underground reservoir comprising placing a first composition comprising a filtering agent in the zone of lost circulation, placing a second composition comprising a crosslinkable polymer system and a charge in the zone of lost circulation, and allow the compositions to be established in the place. The foregoing has very broadly described the features and technical advantages of the present invention in order to better understand the following detailed description of the invention. The additional features and advantages of the invention that will be described after this form the object of the claims of the invention. It should be appreciated by those skilled in the art that the concept and the specific embodiments described can be readily used as a basis for modifying or designing other structures to carry out the same purposes of the present invention. It should also be noted by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.

BRIEF DESCRIPTION OF THE FIGURES For a detailed description of the preferred embodiments of the invention, reference will now be made to the appended figures in which: Figure 1 is a graph of a thickening time test. Figure 2, Figure 3, Figure 4, and the Figure 5 are graphs of a static resistance test of the gel. Figure 6 is a plot of static resistance of the predicted versus observed gel. Figure 7, Figure 8, Figure 9, Figure 10 and Figure 11 are photographs of a lost circulation composition.

DETAILED DESCRIPTION OF THE INVENTION Lost circulation compositions (LCC) are described herein that can be used to block fluid flow through lost circulation zones in an underground reservoir. The LCC may comprise a crosslinkable polymer system and a filler. Alternatively, the LCC may comprise a crosslinkable polymer system, a filler and a filtering agent. LCCs such as those described herein may be used to block fluid flow through paths such as water-filled fractures, voids or cracks in the cement column and casing, etc. In addition, LCCs such as those described herein may be used to improve the borehole pressure holding capacity when introduced into areas of lost circulation. In one modality, the LCC comprises a system crosslinkable polymer. Examples of suitable crosslinkable polymer systems include, but are not limited to, the following: a water-soluble copolymer of a non-acidic ethylenically unsaturated polar monomer and a copolymerizable ethylenically unsaturated ester; a terpolymer or a tetrapolymer of an ethylenically unsaturated polar monomer, an ethylenically unsaturated ester, and a monomer selected from acrylamide-2-methylpropane sulfonic acid, N-vinylpyrrolidone, or both; or combinations thereof. The copolymer can contain from one to three polar monomers and from one to three unsaturated esters. The crosslinkable polymer system may also include at least one crosslinking agent, which is defined herein as a material that is capable of crosslinking such copolymers to form a gel. As used herein, a gel is defined as a reticulated polymer network swollen in a liquid medium. The crosslinking agent may be, for example and without limitation, an organic crosslinking agent such as a polyalkyleneimine, a polyfunctional aliphatic amine such as a polyalkylene polyamine, an aralkylamine, a heteroaralkylamine, or combinations thereof. Examples of suitable polyalkylene imines include without limitation polymerized ethylene imine and propylene imine. Examples of suitable polyalkylene polyamines include without suitable polyethylene and polypropylene polyamines limitation. A description of such copolymers and crosslinking agents can be found in U.S. Patent Nos. 5,836,392; 6,192,986 and 6,196,317, of which each is incorporated herein by reference in its entirety. The ethylenically unsaturated esters used in the crosslinkable polymer system can be formed of a hydroxyl compound and an ethylenically unsaturated carboxylic acid selected from the group consisting of acrylic, methacrylic, crotonic, and cinnamic acids. The ethylenically unsaturated group may be in the alpha-beta or beta-gamma position with respect to the carboxyl group, but may be at a greater distance. In one embodiment, the hydroxyl compound is an alcohol generally represented by the formula ROH, wherein R is an alkyl, alkenyl, cycloalkyl, aryl, arylalkyl, aromatic, or heterocyclic group that can be substituted with one or more than one hydroxyl group , ether, and thioether. The substitute may be on the same carbon atom of the R group which is linked to the hydroxyl group on the hydroxyl compound. The hydroxyl compound can be a primary, secondary, iso, or tertiary compound. In one embodiment, a tertiary carbon atom is linked to the hydroxyl group, for example, t-butyl and trityl. In one embodiment, the ethylenically ester unsaturated is t-butyl acrylate. The non-acidic ethylenically unsaturated polar monomers used in the crosslinkable polymer system can be amides, for example, primary, secondary, and / or tertiary amides, of an unsaturated carboxylic acid. Such amides may be derived from ammonia, or a primary or secondary alkylamine, which may be optionally substituted by at least one hydroxyl group as in alkylol amides such as ethanolamides. Examples of such polar ethylenically unsaturated carboxylic acid monomers include without limitation acrylamide, methacrylamide, and acrylic ethanol amide. In one embodiment, the crosslinkable polymer system is a copolymer of acrylamide and t-butyl acrylate, and the crosslinking agent is polyethylene imine. These materials are commercially available as an adaptation control system that provides H2ZERO service from Halliburton Energy Services. The adaptation control system that provides H2ZERO service is a combination of HZ-10 polymer and HZ-20 crosslinker. HZ-10 is a low molecular weight polymer consisting of polyacrylamide and an acrylate ester. The freezing index of the adaptation control system that provides H2ZERO service is controlled by the unmasking of crosslinking sites in the polymer HZ-20 which is a polyethylene imine crosslinker. The concentrations of the polymer HZ-10 and crosslinker HZ-20 contribute to the reaction time of LCC, its final mechanical characteristics and its stability. In one embodiment, the crosslinkable polymer system forms a viscous gel in about 60 minutes to about 300 minutes, alternately about 60 minutes to about 300 minutes at a temperature of about 82.22 ° C (180 ° F) to about 160 ° C (320 ° F), alternatively about 82.22 ° C (180 ° F) to about 107.22 ° C (225 ° F) and, alternatively about 121,111 ° C (250 ° F) to about 160 ° C (320 ° F). The relative amounts of the HZ-10 polymer and HZ-20 crosslinker suitable for use in the LCC preparation of this disclosure will be described in detail later herein. In one embodiment, the LCC comprises a load. Here, a filler refers to particulate materials, also called very fine filler material, designed to fill the filtration agent of the LCC. Such charges may be smaller in size than the filtering agent. Details of the size of the filtering agent and filler will be described later herein. Such charges can have a pH of about 3 to about 10. In one embodiment, the load has a specific gravity of less than about 1 to about 5, alternatively about 1.5 to about 5, alternatively about 1.75 to about 4. Without wishing to be limited by theory, loads that have a specific gravity in the described range can produce an LCC with greater flexibility and ductility. Examples of suitable fillers include without limitation quaternary alkylammonium montmorillonite, bentonite, zeolites, barite, fly ash, calcium sulfate, and combinations thereof. In one embodiment, the charge is a montmorillonite of quaternary alkylammonium. In one embodiment, the filler is a clay that can be inflated or hydrated with water. In an alternative embodiment, the filler is a petroleum composition for sealing which may comprise a hydratable polymer, an organophilic clay and a clay which can be swollen with water. Such petroleum compositions for sealing are described in U.S. Patent Nos. 5,913,364; 6,167, 967; 6,258,757, and 6,762,156, which are incorporated herein by reference in their entirety. In one embodiment, the loading material is lost circulation material FLEXPLUG, which is a sealing oil composition comprising quaternary alkylammonium montmorillonite. commercially available from Halliburton Energy Services. In one embodiment, the LCC optionally comprises a filtering agent. Examples of filtration agents include, without limitation, elastic materials such as graphite; fibrous materials such as cedar bark, crushed cane sticks and mineral fiber; flake materials such as mica flakes and pieces of plastic or cellophane sheet; and granular materials such as limestone or ground or dimensioned marble, wood, nutshells, formica, corn cobs, gravel and cotton pods. In one embodiment, the filtration agent is an elastic graphite such as STEELSEAL or STEELSEAL FINE lost circulation additives which are commercially available double composition graphite derivatives from Baroid Industrial Drilling Products, a Halliburton Energy Services company. In another embodiment, the filtration agent is a particulate material coated with resin. Examples of suitable resin-coated particulate materials include, without limitation, ground resin-coated marble, resin-coated limestone, and resin-coated sand. In one embodiment, the filtering agent is sand coated with resin. The sand can be classified sand that is dimensioned based on an awareness of the size of the lost circulation zone. The sand classified may have a particle size in the range of approximately 10 to approximately 70 meshes, North American Sieve Series. The classified sand can be coated with a curable resin, a thickening agent or mixtures thereof. The hardenable resin compositions useful for coating sand and consolidating it into a hard, fluid-permeable mass generally comprise a hardenable organic resin and a resin-to-sand coupling agent. Such resin compositions are well known to those skilled in the art, such as their use to consolidate sand into hard, fluid-permeable masses. An amount of such compositions is described in detail in U.S. Patent Nos. 4,042,032, 4,070,865, 4,829,100, 5,058,676 and 5,128,390 of which each is incorporated herein by reference in its entirety. Methods and conditions for the production and use of such resin-coated particulate materials are described in U.S. Patent Nos. 6,755,245; 6,866,099; 6,776,236; 6,742,590; 6,446,722, and 6,427,775, of which each is incorporated herein by reference in its entirety. An example of a suitable resin for coating the particulate material includes without limitation the conductivity enhancement system of SANDWEDGE NT which is a commercially available resin coating of Halliburton Energy Services. In some modalities, additives may be included in the LCC to improve or change the properties thereof. Examples of such devices include but are not limited to salts, accelerators, surfactants, establishment retardants, defoamers, establishment prevention agents, weight materials, dispersants, vitrified shales, reservoir conditioning agents, or combinations thereof. Other mechanical property modification additives, for example, are carbon fibers, glass fibers, metal fibers, mineral fibers, and the like which can be added to further modify the mechanical properties. These additives can be included individually or in combination. Methods for introducing these additives and their effective amounts are known to one of ordinary skill in the art. In one embodiment, the LCC includes a sufficient amount of water to form a pumpable slurry. The water may be fresh water or salt water, for example, an unsaturated aqueous saline solution or a saturated aqueous saline solution such as brine or sea water. In one embodiment, the LCC comprises a crosslinkable polymer system and a filler. In such modality, the The crosslinkable polymer system may be present in an amount of about 35% to about 90% by volume, and the filler may be present in an amount of about 8% to about 40% by volume. Alternatively, the LCC comprises a crosslinkable polymer system, a filler and a filtering agent. In such an embodiment, the crosslinkable polymer system can be present in an amount of about 30% to about 90% by volume, the filler can be present in an amount of about 8% to about 40% by volume, and the filtering agent can be present in an amount of about 1% to about 10% by volume. The components of the LCC can be combined in any order desired by the user to form a slurry that can then be placed in a sounding that experiences lost circulation. The components of the LCC can be combined using any mixing device compatible with the composition, for example, a volumetric mixer. In one embodiment, the components of the LCC are combined at the site of the sounding that experiences lost circulation. Alternatively, the components of the LCC are combined off-site and then subsequently used at the sounding site experiencing lost circulation. The methods for the preparation of a LCC slurry are known to one of ordinary skill in the art. In one embodiment, an LCC is prepared by combining the performance control system providing H2ZERO service of the crosslinkable polymer system with a load, lost flow material FLEXPLUG OBM. In such an embodiment, the LCC is prepared by combining from about 35% to about 90% by volume of the performance control system providing H2ZERO service with about 8% to about 40% by volume of the lost flow material FLEXPLUG OBM. The performance control system providing H2ZERO service is prepared by mixing the low molecular weight polymer HZ-10 consisting of polyacrylamide and an acrylate ester with the polyethylene imine crosslinker HZ-20. The relative amounts of HZ-10 and HZ-20 that will be used in the preparation of H2ZERO can be adjusted to provide gelation within a specific time frame based on the reaction conditions such as temperature and pH. For example, the amount of crosslinker HZ-20 necessary for gelation is inversely proportional to the temperature where higher amounts of HZ-20 are required at lower temperatures to effect the formation of a viscous gel. Additionally, the gelling time can be adjusted to compensate the pH of the loading material. The adjustment of the performance control system that provides H2ZERO service to provide the optimum degree of gelation as a function of temperature and / or pH is known to one of ordinary skill in the art. The load, the lost circulation material FLEXPLUG OBM is a sealing oil composition comprising quaternary alkylammonium montmorillonite. Without wishing to be limited by theory, such oil compositions for sealing may function by the hydratable polymer which reacts with water in the bore to hydrate and immediately form a highly viscous gel. The clay that can be swollen with water then swells immediately in the presence of water and together with the viscous gel forms a highly viscous sealing mass. The organophilic clay can then react with a petroleum carrier fluid to add viscosity to the composition so that the polymer and clay do not harden out of the oil before reacting with water in the borehole. In one embodiment, the LCCs of this description when placed in a zone of lost circulation produce a permanent obturator that is flexible, adhesive and of appreciable compressive strength. In one embodiment, the LCCs of this disclosure have appreciable static resistance to the gel (SGS).

The LCCs described herein may be used as probing service fluids. As used herein, a "service fluid" refers to a fluid used to drill, complete, complement work, fracture, repair, or otherwise prepare a sounding for the recovery of materials residing in an underground deposit penetrated by the sounding. Examples of service fluids include, but are not limited to, cement slurries, drilling fluids or muds, separator fluids, fracturing fluids or completion fluids, all of which are well known in the art. The service fluid is for use in a borehole that penetrates an underground deposit. It should be understood that "underground reservoir" encompasses areas below the exposed ground and areas below the ground covered by water such as the ocean or fresh water. The LCC can be introduced to the sounding to prevent the loss of aqueous or non-aqueous drilling fluids in areas of lost circulation such as empty spaces, vugular zones, and natural or induced fractures while drilling. In one embodiment, the LCC is placed in a borehole as a single stream and is activated by conditions of the borehole to form a barrier that substantially seals the areas of lost circulation. In such modality, the LCC can be placed in the bottom of the perforation through the auger forming a composition that substantially eliminates the lost circulation. In yet another embodiment, the LCC is formed at the bottom of the perforation by mixing a first stream comprising one or more LCC components and a second stream comprising additional LCC components. For example, the LCC may be formed at the bottom of the perforation by mixing a first stream comprising a filtering agent and a second stream comprising a crosslinkable polymer system and a filler. Methods for introducing compositions in a sounding to seal the underground areas are described in U.S. Patent Nos. 5,913,364; 6,167,967; and 6,258,757, of which each is incorporated herein by reference in its entirety. The LCC can form an intact mass without flow within the zone of lost circulation that clogs the zone and inhibits the loss of drilling fluid subsequently pumped, which allows additional drilling. It should be understood that it may be desired to accelerate the viscosity reaction for a fast filling of the empty spaces. Alternatively, it may be desired to prolong or delay the viscosity for a deeper penetration into the void spaces. For example, the LCC can form a mass that clogs the area at elevated temperatures, such as those found at greater depths within a sounding. In one embodiment, LCCs can be used in well completion operations such as primary and secondary cementing operations. The LCC may be placed in an annular area of the borehole and may be allowed to be established so as to isolate the underground deposit from a different portion of the borehole. The LCC thus forms a barrier that prevents fluids in that underground deposit from migrating to other underground deposits. In one mode, the poll in which the LCC is placed belongs to a multilateral polling configuration. It should be understood that a multilateral survey configuration includes at least two main probes connected by one or more auxiliary probes. In secondary cementation, often referred to as compression cementation, the LCC can be strategically placed in the borehole to plug an empty space or a crack in the conduit, to plug an empty space or a crack in the hardened sealant (for example, cement jacket) that resides in the annular zone, to seal a relatively small opening known as an annular microzone between the hardened sealant and the conduit, etc. The various procedures that can be followed to use a sealant composition in a The surveys are described in U.S. Patent Nos. 5,346,012 and 5,588,488, which are hereby incorporated herein by reference in their entirety. In other embodiments, additives are also pumped into the LCC sounding. For example and without limitation, fluid-absorbing materials, resins, aqueous superabsorbents, viscosity agents, suspending agents, dispersing agents, or combinations thereof can be pumped into the stream with the LCCs described. The LCCs of this disclosure can provide control of lost circulation in a period of time sufficiently short to prevent the operator from coming out of the hole and thereby reduce non-productive time of the drilling equipment. Without wishing to be limited by theory, the filtering agent can immediately filter the areas of circulation lost in the underground sounding. The load can then be compressed in the areas of lost circulation that form a bridge between the larger filtering agent. Finally, the thermally activated crosslinkable polymer system can be gelled in place to produce a permanent obturator that is flexible, adhesive, and of appreciable compressive strength. In addition, due to the load inside the grout, the amount of crosslinkable polymer system Compressed in the surrounding rock matrix can be minimized thereby providing a finite layer of rock adjacent to the obturator which has negligible permeability and prevents damage to the reservoir.

EXAMPLES In the invention that has been generally described, the following examples are provided as particular embodiments of the invention and demonstrate the practice and advantages thereof. It is understood that the examples are provided by way of illustration and are not intended to limit the specification of the claims in any way.

COMPARATIVE EXAMPLE The ability of the adaptive control system that provides H2ZERO service to produce an adequate LCC was evaluated. The adaptation control system that provides H2ZERO service is a crosslinkable polymeric system commercially available from Halliburton Energy Services. A slurry of the adaptation control system was designed that provides H2ZERO service for temperatures in the range of 48.88 ° C to 87.77 ° C (120 ° F to 190 ° F), which contained an extremely high percentage of HZ-20, Table 1.

Table 1 Two samples of the adaptation control system product that provides H2ZERO service were mixed and placed in a 54.44 ° C (130 ° F) water bath overnight to confirm that the formula will gel within a reasonable time to the Lowest temperature. Both samples formed a gel of clear appearance that was strong but could not withstand the impact and showed no qualitatively perceptible flexibility. Also, when the product was compressed in excess, its failure mode was similar to bursting. The product separated easily.

EXAMPLE 1 The ability of the adaptation control system providing H2ZERO service to form a LCC with a lost flow material of FLEXPLUG OBM was evaluated. The lost circulation material of FLEXPLUG OBM is a commercially available petroleum seal composition from Halliburton Energy Services. The adaptation control system that provides H2ZERO service had an adverse effect on the latex contained within the grout of the lost circulation material of FLEXPLUG OBM. The lost circulation material of FLEXPLUG OBM was then used as a dry mix load in the slurry of the adaptation control system that provides H2ZERO service. A grout of 9.3 ppg was targeted as this is the grout density of typical lost circulation material of FLEXPLUG OBM. Figure 2 lists the components and quantities used to design the H2ZERO / FLEXPLUG OBM slurry.

Table 2 The samples were heated overnight in a water bath at 54.44 ° C (130 ° F). The final gelled product was very different from the gelled product of the adaptation control system providing H2ZERO service described in the Comparative Example. The gelled product of H2ZERO / FLEXPLUG OBM showed greater flexibility, increased toughness, improved elasticity, and improved impact durability. In addition, the gelled product of H2ZERO / FLEXPLUG OBM remained "sticky" unlike the system of Adaptation control that provides H2ZERO service. The previous slurry was then tested for pumping capacity in an HPHT Consistometer at a constant pressure of 68,948 bar (1000 psi). The temperature was programmed to start the test at 26.66 ° C (80 ° F), to rise to 54.44 ° C (130 ° F) for a period of one hour, and then rise to 87.77 ° C (190 ° F) during a two-hour period. Table 3 contains the consistency readings of this test that is also represented graphically in Figure 1.

Table 3 Bearden Consistency Typically, a fluid is considered "non-pumpable" once it exceeds 70 Be. The results show that the compositions remain pumpable until they reach the desired temperature at which point they quickly form a highly flexible, durable and adhesive product.

EXAMPLE 2 A slurry was prepared as described in Example 1 and SGS was determined as a function of temperature. The static test of gel resistance development requires specialized equipment, such as the MACS Analyzer or the INIMACS Analyzer. This equipment measures the resistance to the deformation of a grout under temperature and pressure of the bottom of the perforation while the grout remains essentially static. The test is carried out by mixing the slurry and placing it in the specialized test device. The slurry is then stirred and heated to a drilling bottom circulation temperature (BHCT) and the bottomhole pressure according to the same schedule as the thickening time test. After the slurry reaches the BHCT, the agitation is stopped and the slurry is allowed to remain essentially static. The stirring paddle is rotated at a speed of approximately 0.5 Vrnin., While the deformation resistance in the paddle is measured. The resistance to deformation is correlated with SGS (the units are in (lbf / 100 ft2) and an SGS development scheme is performed as a function of time Figure 2 is a graph of the results of a SGS test carried out out at 26.66 ° C (80 ° F), Figure 3 is a graph of the results of an SGS test carried out at 54.44 ° C (130 ° F), Figure 4 is a graph of the results of an SGS test carried out at 71.11 ° C (160 ° F), and Figure 5 is a graph of the results of an SGS test carried out at 87.77 ° C (190 ° F). The results demonstrate the formation of static resistance to the gel more rapidly at increased temperatures.

EXAMPLE 3 An additional formulation of H2ZERO / FLEXPLUG OBM was prepared according to Table 4.

Table 4 The materials in Table 4 were mixed in a MINIMACS for 25 minutes at 68.94 bars (1000 psi) until they reached the pre-set temperature of 26.66 ° C (80 ° F), 54.44 ° C (130 ° F), 71.11 ° C (160 ° F) or 87.77 ° C (190 ° F). Then, the MINIMACS remained static at t = 30 minutes and SGS (lbf / 100 square feet) was recorded against time. Four tests were carried out, one at each of the given temperatures. Raw data from SGS are provided in Table 5. Analysis of the data revealed the need to model SGS as a function of an "alternate time" defined as follows: Alternating time = t - t0ffSet, T (1) Where: t = mixing time, with t = 0 materials added to the mixing container; t = 30 minutes were for static conditions; and t0ffSet / T = compensation time (minutes) at the reference point temperature of T (F). The ambient temperature tests (26.66 ° C (80 ° F)) never exceeded 18,144 kg-force / 9.29 square meters (40 lbf / 100 square feet), thus indicating that a certain initial minimum temperature is required to initiate the reactions kinetics that produce theological changes resulting in substantial resistance to the gel. It is assumed that SGS is a direct indicator of the LCC performance point. Figure 6 contains SGS against time data for the samples of 54.44 ° C (130 ° F), 71.11 ° C (160 ° F) and 87.77 ° C (190 ° F) together with the prediction fit of the generalized model in Equation (2).

SGS = (t - toffset / r) "r where: O¡T is the" pseudo-reaction proportion constant "which is a function of temperature.

Table 5 Table ß Parameters: &T toffset, t The results show that deploying the concept of "time change" resulted in a simple but very precise model for the three temperatures tested. Values of the best fit of the parameters in Equation (2) are given in Table 6. Notice how the exponent of reaction rate, aTf is a function of temperature, as well as the parameter of "change of time" t0ffset, r- Also provided in Table 6 is "time to achieve SGS = 226.79 kg-force / 9.29 square meters (500 lbf / 100 square feet) "and observe its sensitivity to temperature as well.

EXAMPLE 4 Preliminary measurements of the mechanical properties of the gelled product of H2ZERO / FLEXPLUG OBM were carried out. For the base grout formula provided in Tables 2 and 4, the rudimentary test in order to capture the ordinary compressive strength estimates and the visual representations of flexibility and elasticity were performed on three samples of the resulting product. These tests were performed by placing the samples on a Tinius-Olsen machine and gradually increasing the compression load, while measuring the change in height. The Tinius-Olsen machine is used to test the compressive strength. The compression load was increased until the sample showed failure in the form of permanent deformations in the axial direction. The elasticity was shown by the product that returned almost to its original height and diameter when the charges were released. In all three cases, the sample returned to its original form to the point of failure. As can be seen from the photographs taken of a failed sample in Figure 11, even in this moment the sample almost returns to its original form. Figure 7 shows a sample with original dimensions of 7.62 centimeters in diameter (3 inches) and a height of 5.08 centimeters in diameter (2 inches) with a compressive load of 22.68 kg (50 Ib) applied. The sample, under this load, had been deformed to a height of approximately 2.54 centimeters (1 inch) and a diameter of approximately 10.16 / 0.636 centimeters (4-1 / 4 inches). Figure 8 shows this same sample under a compression load of 45,359 kg (100 Ib). The sample, under this load, it had deformed to a height of approximately 1.27 centimeters (1/2 inches) and a diameter of approximately 15.24 centimeters (6 inches). Figure 9 shows this same sample after the load of 45,359 kg (100 Ib) has been removed. The sample has returned to its original dimensions and shape without perceptible permanent deformation. A similar result was obtained when the sample was subjected to a compression load of 68,039 kg (150 Ib) (not shown). Figure 10 shows this same sample under a compression load of 90,718 kg (200 Ib). As can be seen from the presence of cracks along the specimen diameter, the sample has now failed. Since the failure detection was purely through visual confirmation, it can only be established that the specimen failed between 68,039 kilograms (150 pounds) and 90,718 kilograms (200 pounds) of compression force. Figure 11 shows the sample failed after it is taken from Tinius-Olsen. As can be seen in this photograph, the sample returns almost to its original shape even after the rupture in the form of a "stellar explosion".

EXAMPLE 5 The compression tests described in Example 4 were repeated with two smaller samples with a height of 2.54 centimeters (1 inch) and a diameter of 5.08 centimeters (2 inches). The results were similar to those observed with the largest sample. In general, all three tests demonstrated that a sample can be deformed by approximately 27% of its original height and 2 times the original diameter before the repeatable failure of the stellar burst rupture occurs. The failure seems to be more dependent on the deformation limitations that the specimen may experience, rather than the applied pressure. For example, in the smaller diameter samples, he again took between 68,039 kilograms (150 pounds) and 90,718 kilograms (200 pounds) of compression load before the sample failed. For the smallest sample, this equals more than twice the pressure at the fault that shows the largest sample, but it seems that both samples failed at approximately the same percentage reduction in height.

EXAMPLE 6 In addition to the compression load tests, two large synthetic rock checks of 15.24 centimeters (6 inches) with fractures that were tapered from 4.5 mm to 1.5 mm were filtered with the H2ZERO / FLEXPLUG OBM slurry containing a mixture of STEELSEAL FINE and BARACARB 600 products as the filtration agent, Table 7. BDF-391 and BDF-393 are lost circulation additives with a particle size distribution of d50 of about 725 and 1125 microns respectively. The particle size distribution of d50 specifies a size for which 50% of the total volume of particles is smaller in size than the value. The particulate materials of the filtering agent were added to achieve a charge of 80 ppb. The STEELSEAL FINE lost circulation additive is an elastic graphite material commercially available from Halliburton Energy Services. The bonding agent of BARACARB 600 is a commercially available calcium carbonate available from Halliburton Energy Services.

Table 7 The controls were filtered in the Extrusion Rheometer in a Tinius-Olsen machine. Both controls were filtered at a pressure of approximately 19,305 bar (280 psi). The controls were then heated in a water bath at 87.77 ° C (190 ° F) overnight. Each witness was then placed on the Hassler Sleeve Removal Apparatus and pressurized until the fracture plug failed. The first witness was evacuated to 56,537 bar (820 psi) and the second evacuated to 44,126 bar (640 psi). In comparison, the lost flow material of FLEXPLUG OBM tends to fail at pressures of 10,342 bar (150 psi) or less in this same fracture geometry.

EXAMPLE 7 The filler materials with the exception of the lost dry mix circulation material of FLEXPLUG OBM were used to produce slurries similar to that listed in Table 4 for the purpose of qualitative comparison of such perceivable characteristics as flexibility, gel time and Firmness The loads investigated, and the relative degree of the resulting product properties are listed in Table 8. The dry blend of FLEXPLUG OBM appears to have produced the most favorable end product due to its extreme flexibility, durability, elasticity and tack. lost circulation material of FLEXPLUG W is a composition for sealing, the FLY ASH retardant is a carbon combustion product, the CAL SEAL gypsum additive is a plaster cement, the additive FDP-C661-02 and the acceleration component FDP-C661VA-02 are compression strength accelerators, all of which are commercially available from Halliburton Ene rgy Services. The weighting material of BAROID is barium sulfate, which is commercially available from Baroid Industrial Drilling Products a company of Halliburton Energy Services. The lost circulation material of FLEXPLUG OBM was the only proven load that produced a final product with appreciable "stickiness".

Table 8 EXAMPLE 8 Various traditional particulate filtration agent products were used to produce slurries similar to that listed in Table 4 for the purpose of qualitative comparison of perceptible characteristics such as flexibility, gel time and firmness. The lost circulation seal of HYDROPLUG is a self-expanding lost circulation material commercially available from Halliburton Energy Services. For each agent of filtration or filtration material, the formula of the slurry listed in Table 4 was charged in an equivalent of 80 ppb of the filtering agent. Table 9 lists the observations of the final products with these various filtering agents. The filtration quality was determined by how different the filtration (segregated) layer was. If the filtering agent remained dispersed, an Acceptable grade was provided where a filtering agent that created a filtration layer, thickly delineated, was given an excellent degree.

Table 9 EXAMPLE 9 A base slurry was prepared as described in Tables 2 and 4. To this base slurry was added lOOg of gravel coated with the SANDWEDGE conductivity enhancement system as the filtering agent. The resulting material displayed improved elasticity and flexibility when compared to the resin-free gravel-free composition. It has been found that by adding the charge of the dry mixture of lost flow material from FLEXPLUG OBM to the adaptation control system providing H2ZERO service of the crosslinkable polymer system in combination with a number of particulate filtration agent products, a highly flexible, durable and adhesive product is formed. This product, through the filtering agent of particulate materials, provides an immediate short-term shutter so that the driller can continue to drill forward. In addition, the thermally activated gel of FLEXPLUG / H2ZERO produces a long-term obturator that also creates a limited zone of invasion within the surrounding rock matrix, creating a largely reduced permeability zone to further strengthen the obturator. While preferred embodiments of the invention have been shown and described, modifications thereof can be made by one of skill in the art without departing from the spirit and teachings of the art. invention. The embodiments described herein are exemplary only, and are not intended to be limited. Many variations and modifications of the invention described herein are possible and are within the scope of the invention. Where numerical margins or limitations are expressly stated, such express margins or limitations must be understood to include margins or iterative limitations of similar magnitude that fall within the margins or limitations expressly stated (eg, from about 1 to about 10 includes, 2 , 3, 4, etc., greater than 0.10 includes 0.11, 0.12, 0.13, etc.). The use of the term "optionally" with respect to any element of a claim is intended to mean that the subject element is required, or alternatively, is not required. Both alternatives are intended to be within the scope of the claim. The use of broader terms for example, comprises, includes, having, etc., should be understood to provide support for narrower terms such as consisting of, consists essentially of, substantially comprised of, etc. Accordingly, the scope of protection is not limited by the description set forth in the foregoing but is limited only by the claims that follow, that scope includes all equivalents of the subject object of the claims. Each claim is incorporated in the specification as one embodiment of the present invention. A) Yes, the claims are a further description and are an addition to the preferred embodiments of the present invention. The discussion of a reference herein is not an admission since it is the prior art to the present invention, especially any reference that may have a publication date after the priority date of this application. The descriptions of all patents, patent applications, and publications cited herein are hereby incorporated by reference, to the extent that they provide exemplary, procedural, or other details supplemental to those set forth herein.

Claims (40)

1. NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and therefore the claim described in the following claims is claimed as property CLAIMS 1. A circulation composition lost for use in a sounding characterized in that it comprises a crosslinkable polymer system and a filler. The composition according to claim 1, characterized in that the crosslinkable polymer system comprises a water-soluble copolymer of a non-acidic ethylenically unsaturated polar monomer and a copolymerizable ethylenically unsaturated ester; a water-soluble terpolymer or tetrapolymer of an ethylenically unsaturated polar monomer, an ethylenically unsaturated ester, and a monomer selected from acrylamide-2-methylpropane sulfonic acid, N-vinylpyrrolidone, or both; or combinations thereof; and wherein the crosslinking agent comprises a polyalkyleneimine, a polyfunctional aliphatic amine, an aralkylamine, a heteroaralkylamine, or combinations thereof. 3. The composition according to claim 1, characterized in that the system crosslinkable polymer comprises a copolymer of acrylamide and t-butyl acrylate and the crosslinking agent comprises polyethylene imine. . The composition according to claim 1, characterized in that the crosslinkable polymer system is thermally activated. The composition according to claim 4, characterized in that the thermal activation occurs from about 82.22 ° C (180 ° F) to about 160 ° C (320 ° F). The composition according to claim 1, characterized in that the crosslinkable polymer system is present in an amount of about 35% to about 90% by volume. The composition according to claim 1, characterized in that the crosslinkable polymer system forms a viscous gel of about 60 minutes to about 300 minutes. The composition according to claim 1, characterized in that the filler comprises quaternary alkylammonium montmorillonite, bentonite, zeolites, barite, fly ash, calcium sulfate, or combinations thereof. 9. The composition according to claim 3, characterized in that the charge comprises quaternary alkylammonium montmorillonite. The composition according to claim 1, characterized in that the filler has a pH from about 3 to about 10. The composition according to claim 1, characterized in that the filler comprises a hydratable polymer, an organophilic clay, a clay that can be swollen in water, or combinations thereof. The composition according to claim 1, characterized in that the filler has a specific gravity of less than about 1 to about 5. The composition according to claim 1, characterized in that the filler is present in an amount of about 8% to about 40% by volume. 14. The composition according to claim 1, further characterized in that it comprises a filtering agent. 15. The composition according to claim 14, characterized in that the filtering agent is an elastic material, a fibrous material, a flake material, a granular material, or combinations thereof. 16. The composition according to claim 14, characterized in that the filtering agent is a particulate material coated with resin. 17. The composition according to claim 14, characterized in that the filtering agent is present in an amount of about 1% to about 10% by volume. 18. The composition according to claim 9, further characterized in that it comprises a particulate material coated with resin as a filtering agent. 19. The composition according to claim 18, characterized in that the filler also comprises a hydratable polymer. The composition according to claim 19, characterized in that the filler also comprises an organophilic clay. 21. A method for serving a sounding in contact with an underground reservoir, characterized in that it comprises: placing a probing service fluid comprising a crosslinkable polymer system and a charge in a circulation zone lost within the probing. 22. The method according to claim 21, characterized in that the system crosslinkable polymer comprises a water-soluble copolymer of a non-acidic ethylenically unsaturated polar monomer and a copolymerizable ethylenically unsaturated ester; a water-soluble terpolymer or tetrapolymer of a polar ethylenically unsaturated monomer, an ethylenically unsaturated ester, and a monomer selected from acrylamide-2-methylpropane sulfonic acid, N-vinylpyrrolidone, or both; or combinations thereof; and wherein the crosslinking agent comprises a polyalkyleneimine, a polyfunctional aliphatic amine, an aralkylamine, a heteroaralkylamine, or combinations thereof. The method according to claim 21, characterized in that the crosslinkable polymer system comprises a copolymer of acrylamide and t-butyl acrylate and the crosslinking agent comprises polyethylene imine. 24. The method according to claim 21, characterized in that the crosslinkable polymer system is thermally activated. 25. The method according to claim 24, characterized in that the thermal activation occurs from about 82.22 ° C (180 ° F) to about 160 ° C (320 ° F). 26. The method of compliance with claim 21, characterized in that the crosslinkable polymer system is present in an amount of about 35% to about 90% by volume. 27. The method according to claim 21, characterized in that the crosslinkable polymer system forms a viscous gel of about 60 minutes to about 300 minutes. The method according to claim 21, characterized in that the filler comprises quaternary alkylammonium montmorillonite, bentonite, zeolites, barite, fly ash, calcium sulfate, or combinations thereof. 29. The method according to claim 1, characterized in that the charge comprises quaternary alkylammonium montmorillonite. 30. The method according to claim 21, characterized in that the filler has a pH from about 3 to about 10. The method according to claim 21, characterized in that the filler comprises a hydratable polymer, an organophilic clay, a clay that can be swollen in water, or combinations thereof. 32. The method according to claim 21, characterized in that the load has a specific gravity of less than about 1 to about 5. The method according to claim 21, characterized in that the filler is present in an amount of about 8% to about 40% by volume. 34. The method according to claim 21, further characterized in that it comprises a filtering agent. 35. The method according to claim 34, characterized in that the filtering agent is an elastic material, a fibrous material, a flake material, a granular material, or combinations of the same. 36. The method according to claim 34, characterized in that the filtering agent is a particulate material coated with resin. 37. The method according to claim 34, characterized in that the filtering agent is present in an amount of about 1% to about 10% by volume. 38. The method according to claim 21, characterized in that the probing service fluid is placed as a simple stream in the underground sounding. 39. A method for blocking the flow of fluid through a zone of circulation lost in an underground reservoir characterized in that it comprises: (a) placing a first composition comprising a filtering agent in the zone of lost circulation; (b) placing a second composition comprising a crosslinkable polymer system and a charge in the lost circulation zone; and (c) allow the compositions to be established in place. 40. The method according to claim 39, characterized in that the filtering agent is a particulate material coated with resin, an elastic material, a fibrous material, a flake material, a granular material, or combinations thereof.