RU2561630C2 - Biopolymer drilling mud sbk-uni-drill-pro (hard) - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to clayless biopolymer drilling muds, which are used to drill in severe mining and geological conditions. The biopolymer drilling fluid contains, wt %: low-viscosity polyanionic cellulose (degree of substitution 0.9, Brookfield dynamic viscosity <100 mPa·s) 0.2-1.5; high-viscosity polyanionic cellulose (degree of substitution 0.9, Brookfield dynamic viscosity >1000 mPa·s) 0.2-1.5; xanthane-type biopolymer 0.1-0.6; lubricant additive 0.07-3.5; alkali and/or alkali-earth metal salts KCl, NaCl, CaCl₂, MgCl₂, bischofite 3.0-40.0; sodium hydroxide 0.1-0.6; glycoil reagent inhibitor 0.5-1.0; bactericide 0.01-0.2; different-fraction filler - barium sulphate up to 80; water - the balance.

EFFECT: improved structural-rheological properties and heat resistance, salt resistance, reduced harmful environmental effect, fewer and lower concentration of components required to prepare the drilling mud, while maintaining inhibiting, lubricant, filtration and anti-seize properties.

3 cl, 1 dwg, 5 tbl, 3 ex

Description

The invention relates to polymer drilling fluids for drilling gas and oil wells, in particular to clayless biopolymer drilling fluids that are used for drilling in difficult geological conditions, including chemogenic deposits and at high bottomhole temperatures, as well as directional and horizontal sections of wells.

Known biopolymer drilling fluid designed for drilling directional and horizontal wellbores (Russian patent No. 2236429, IPC 7 C09K 7/02, publ. September 20, 2004, No. 26), which contains, by weight. %: xanthan biopolymer type Flo-Vis - 0.3-0.5, humate reagent (powder carbon-alkaline reagent - PUSHR) - 10.5-15.0, water - the rest. The disadvantage of this solution is low heat resistance (up to 80 ° C) and low resistance to the effects of polyvalent metal ions.

Known biopolymer drilling fluid (PROTOTYPE) (RF patent No. 2289603, IPC C09K 8/10 dated 04/13/2005, publ. 12/20/2006) containing a polymer filter reducing agent, xanthan-type biopolymer, surfactant, lubricant and water, in as a surfactant and a lubricant additive of ethylene diamides of fatty acids, the condensation product of ethylene diamine and phosphatide concentrate, as a polymeric filter reducing agent, polyanionic cellulose, or carboxymethyl cellulose, or carboxymethyloxyethyl cellulose, or hydroxyethyl cellulose, or hydrolyzed polyacrylonitrile, and optionally alkali metal humates — carbon-alkali reagent UCHR or potassium hydrogenate-humate reagent and alkali and / or alkaline earth metal salts — KCl, NaCl, CaCl ₂ , MgCl ₂ , bischofite in the following ratio of components, wt. %:

The specified filtering agent 0.1-1.0

Xanthan Biopolymer 0.2-0.5

The specified fatty acid ethylene diamides 0.05-3.0

USR or GKR 3.0-6.0

Indicated salts 3.0-40.0

Water - the rest

The disadvantage of the biopolymer drilling fluid of the prototype is the lack of structural and rheological properties, namely, low retention, tolerance, lubrication and inhibitory ability.

Modern environmental standards require the use of fresh water-based drilling fluids, but most traditional high-density fluids contain a significant amount of weighting agents, which can reduce penetration rate, increase equivalent circulation density, and cause weighting sedimentation and completion problems.

The objective of the proposed technical solution is to obtain a highly inhibitory composition of the drilling fluid for opening productive formations (including horizontal wells) in unstable sediments, which has a high holding, carrying, lubricating and inhibitory ability, satisfying high environmental requirements for preserving the natural environment.

The technical result of the invention is to increase the structural and rheological properties and heat resistance, to ensure salt resistance, to reduce the harmful effects on the environment, as well as to reduce the number and concentration of components necessary for the preparation of drilling mud while maintaining inhibitory, lubricating, filtering and anti-seizing properties.

The technical result is achieved in that the SBK-UNI-DRILL-PRO (HARD) biopolymer drilling fluid contains polyanionic cellulose, xanthan type biopolymer, a lubricant, alkali and / or alkaline earth metal salts KCl, NaCl, CaCl ₂ , MgCl ₂ , bischofite, this as a lubricant additive contains a fatty acid product of triglycerides with the number of carbon atoms from 14 to 24 and additionally contains an inhibitor reagent glycoil, a different-fraction weighting agent - barium sulfate, sodium hydroxide in the following ratio, wt. %:

low viscosity polyanionic cellulose (grade 0.2-1.5 substitution 0.9, dynamic viscosity <100 MPa · s - according to the Brookfield method) high polyanionic cellulose 0.2-1.5 degree of viscosity (degree of substitution of 0.9, dynamic viscosity> 1000 MPa · s - according to the Brookfield method) xanthan type biopolymer 0.1-0.6 lubricant additive 0.07-3.5 salts of alkali and / or alkaline earth metals 3.0-40.0 KCl, NaCl, CaCl ₂ , MgCl ₂ , bischofite sodium hydroxide 0.1-0.6 glycoil reagent inhibitor 0.5-1.0 bactericide 0.01-0.2 multifraction weighting agent - barium sulfate up to 80 water rest

The components of the inventive drilling fluid

Xanthan type biopolymers. They are water-soluble powder polysaccharides obtained by treatment with xanthonamas bacteria.

PAC BB (KMTS-9v), PAC HB (KMTS-9n) does not have toxic and irritating effects (see TU 2231-002-68730626-2011) - they are used as a polymer filter reducing agent.

Caustic soda belongs to the second hazard class (see GOST 2263-79).

Inhibitor (lubricant based on glycols): glycoil is an organic clay inhibitor that improves the lubricating properties of a solution (TU 0252-001-93231287-2006).

The reagent glycoil PG-40 (OAO Nizhnekamskneftekhim) is an ethylene oxide (propylene) oligomer obtained by alkaline polymerization of ethylene oxide (propylene), TU 2422-130-05766801-2003.

Bactericide (LPE-32 - NPO Technolog) - provides complete suppression of sulfate-reducing bacteria, complete solubility in water eliminates oil pollution and ensures effective disinfection of adhesive forms of bacteria in stagnant zones.

The bactericide belongs to hazard class 3, and when using it, precautionary measures must be observed (see TU 2458-324-05765670-2008).

Salts of alkali and / or alkaline earth metals (KCl, NaCl, CaCl ₂ , MgCl ₂ , bischofite) receive: KCl according to GOST 4568-95, NaCl according to GOST 13830-68, CaCl ₂ according to GOST 450-77, MgCl ₂ or bischofite according to GOST 7759-73.

As a lubricant additive, a triglyceride fatty acid product with a carbon number of 14 to 24 can be used.

The invention is shown in the examples described below.

Preparation and cleaning of the drilling fluid during the well drilling process is carried out using standard equipment.

The drilling fluid preparation unit should include a tank (fluid preparation unit) equipped with mechanical stirrers and an ejector for introducing bulk reagents.

Example 1. A method of preparing 1 m ^{3 of} drilling fluid with beats. weighing 1120 kg / m ³ with a concentration of biopolymer "Barazan D" (xanthan reagent - Halliburton / Baroid) 0.2% wt. is as follows:

To prepare 1 m ^{3 of} drilling fluid with a density of 1120 kg / m ³ (on a fresh basis), the following reagents are successively introduced in a percentage ratio: Barazan D 0.2% PAC BB (LLC Cellikom) 1.2%

PATs NV (LLC “Cellikom”) 1.2% Bactericide (LET-32 - NPO Technolog) 0.01% NaOH (Soda OJSC) 0.01% Bishofit (LLC "Neftegazkhimkomplekt" 2.0% TU 2152-002-93524115-2010) Calcium chloride (TD "HIMPRM" GOST 450-77) 2.0% Reagent glycoil PG-40 (OAO Nizhnekamskneftekhim) 1,0% Barite weighting compound (OJSC Barit Urala) 15.0% Water rest

The reagents are introduced sequentially in this order, with Barazan D, CMC-9n (PAC HB) and CMC-9v (PAC BB) are introduced through the ejector with an interval of 15 minutes per 1 bag of reagent. Otherwise, the formation of polymer lumps is possible, which in the future will not be able to completely dissolve.

Example 2. The method of preparation of 1 m ^{3 of} drilling fluid with a specific weight of 1350 kg / m ³ with a concentration of biopolymer "Barazan D" (xanthan reagent - Halliburton / Baroid) 0.4% wt. It is as follows.

To prepare 1 m ^{3 of} drilling fluid with a density of 1350 kg / m ³ , the following reagents are introduced sequentially in a percentage ratio:

Barazan d 0.4% PAC BB (LLC "Cellikom") 1.2% PATs NV (LLC “Cellikom”) 1.2% Bactericide (LET-32 - NPO Technolog) 0.01% NaOH (Soda OJSC) 0.01% Bishofit (LLC "Neftegazkhimkomplekt" 2.0% TU 2152-002-93524115-2010) Calcium chloride (TD "HIMPRM" GOST 450-77) 2.0% Reagent glycoil PG-40 (OAO Nizhnekamskneftekhim) 1,0% Barite weighting compound (OJSC Barit Urala) 37.0% Water rest

The reagents are introduced sequentially in this order, with Barazan D, KMTs-9n and KMTs-9v introduced through the ejector with an interval of 15 minutes per 1 bag of reagent. Otherwise, the formation of polymer lumps is possible, which in the future will not be able to completely bloom.

Example 3. The method of preparation of 1 m ^{3 of} drilling fluid with a specific weight of 1700 kg / m ³ with a concentration of biopolymer "Barazan D" (xanthan reagent Halliburton / Baroid) 0.6% wt. It is as follows.

To prepare 1 m ^{3 of} drilling fluid with a density of 1700 kg / m ³ , the following reagents are introduced sequentially in a percentage ratio:

Barazan d 0.6% PAC BB (LLC "Cellikom") 1.2% PATs NV (LLC “Cellikom”) 1.2% Bactericide (LET-32 - NPO Technolog) 0.01% NaOH (Soda OJSC) 0.01% Bishofit (LLC "Neftegazkhimkomplekt" 2.0% TU 2152-002-93524115-2010) Calcium chloride (TD "HIMPRM" GOST 450-77) 2.0% Reagent glycoil PG-40 (OAO Nizhnekamskneftekhim) 1,0% Barite weighting compound (OJSC Barit Urala) 80.0% Water rest

The mud properties described in the examples were measured by API R.P. 13 B-1 (water-based mud control method). Table 1 shows examples of the preparation of SBP-UNI-DRILL-PRO (HARD) biopolymer drilling fluids at various concentrations of components and at different densities.

For each example with a certain density ρ, the following parameters were determined:

Т - conditional viscosity, Ф - filterability, PV - plastic viscosity, AV - apparent viscosity, YP - dynamic shear stress, GelsAPI _{10 sec / 10 min} - static shear stress

Table 2 shows the comparative parameters of the biopolymer drilling fluid SBK-UNI-DRILL-PRO (HARD) with the prototype - patent RU No. 2289603, where T is the viscosity

^τ dPa - dynamic shear stress (SI system)

СНС 10/10, dPa-GelsAPI _{10 sec / 10 min} , dPa (SI system) - static shear stress

^η mPa · s - PV, mPa · s - plastic viscosity (SI system).

The inventive biopolymer drilling fluid has a density of from 1040 kg / m ³ to 1700 kg / m ³ .

The thermal stability of polymers also ensures the stability of the rheological and filtration properties of the system at bottomhole temperatures above 177 ° C.

The increased inhibitory effect (due to the synergistic effect of the inhibitor and polymers) allows the use of SBK-UNI-DRILL-PRO (HARD) biopolymer drilling mud when drilling in highly active clays.

Inhibition tests were performed on a longitudinal rock swelling tester in the OFITE dynamic mode.

The diagram (Fig. 1) shows a graph of the comparative swelling of the Kynov mudstones in the environment of biopolymer drilling fluid SBK-UNI-DRILL-PRO (HARD) in comparison with fresh water (% swelling depending on the day).

Check for thermal stability was carried out on an OFITEHPHT filter press (at a temperature of 180 ° C) during heating for 4 hours. The results are summarized in table 3.

The thermal stability of the inventive polymer drilling fluid is shown in table 5.

The inhibitory properties of salts, as you know, are noticeably manifested starting with a concentration of 3.0%, which is due to the lower threshold of salt concentration.

Due to the high salinity of the proposed drilling fluid formulation, the upper threshold for salt concentration is limited only by the limit of their solubility in water, which makes it possible to use such a solution when drilling in chemogenic deposits.

A decrease in the concentration of the biopolymer negatively affects the structural and rheological properties, while the resistance of the solution to alkali and alkaline earth metal salts and the effect of high temperatures are reduced. An increase in the concentration of the biopolymer from above is impractical, since the consumption of chemicals increases, and the structural-rheological and filtration properties are not significantly improved.

The use of polymer filtration reducers in the given concentrations provides a low rate of filtration of biopolymer drilling mud even with the aggression of salts of polyvalent metals. Increasing their concentration above is economically and technologically impractical.

SBK-UNI-DRILL-PRO (HARD) biopolymer drilling mud improves drilling efficiency and also significantly reduces the risk of formation damage. The low volumetric solids content allows reuse of the solution in the following wells. The increased inhibitory effect (due to the synergistic effect of the inhibitor and polymers) allows the use of SBK-UNI-DRILL-PRO (HARD) biopolymer drilling mud when drilling in highly active clays. The use of SBK-UNI-DRILL-PRO (HARD) biopolymer drilling mud when opening the reservoir is possible due to the reduced concentration of the solid phase, a thin impermeable filter cake and environmental safety.

Its monovalent structure reduces the possibility of the formation of insoluble sediments and makes them compatible with most minerals and fluids of the reservoir, as well as compatible with all polymers and thickeners and reagents for controlling water loss, which are part of the solutions for the initial opening of reservoirs.

The inhibitory nature of SBK-UNI-DRILL-PRO (HARD) biopolymer drilling mud allows it to be used with high efficiency for drilling highly active clays.

The thermal stability of polymers also ensures the stability of the rheological and filtration properties of the system at bottomhole temperatures above 177 ° C.

SBK-UNI-DRILL-PRO (HARD) biopolymer drilling mud provides minimal pressure loss during circulation and maximum hydraulic power transmitted to the bit and downhole motor, which allows them to be used for horizontal and super-deep wells (wells with a large deviation from the bottom) .

The claimed technical solution meets the criteria of "novelty" and "inventive step", since no similar technical solutions have been identified in the art, and it is not explicitly obvious to a specialist.

The claimed technical solution meets the criterion of "industrial applicability", since the claimed composition can be obtained from known means and known methods.

Claims (3)

1. Biopolymer drilling fluid containing polyanionic cellulose, xanthan type biopolymer, lubricant, alkali and / or alkaline earth metal salts KCl, NaCl, CaCl ₂ , MgCl ₂ , bischofite, characterized in that it contains a triglyceride fatty acid product with the number of carbon atoms from 14 to 24 and additionally contains an inhibitor of the reagent glycoil, a different-fraction weighting agent - barium sulfate, sodium hydroxide in the following ratio of components, wt. %:
polyanionic cellulose low viscosity (degree of substitution 0.9, dynamic viscosity <100 MPa · s - according to the Brookfield method) 0.2-1.5 polyanionic cellulose high viscosity (degree of substitution 0.9, dynamic viscosity> 1000 MPa · s - according to the Brookfield method) 0.2-1.5 xanthan type biopolymer 0.1-0.6 lubricant additive 0.07-3.5 salts of alkali and / or alkaline earth metals KCl, NaCl, CaCl ₂ , MgCl ₂ , bischofite 3.0-40.0 sodium hydroxide 0.1-0.6 glycoil reagent inhibitor 0.5-1.0 bactericide 0.01-0.2 multifraction weighting agent - barium sulfate up to 80 water rest 2. The drilling fluid according to claim 1, characterized in that the xanthan type biopolymer can be any xanthan based polysaccharide. 3. The drilling fluid according to claim 1, characterized in that the inhibitor contains glycoil PG-40 reagent.

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