SU1710710A1 - Hydraulic fracture of fluid - Google Patents

Description

to a subsequent decrease in well production. The fluid has a high hydraulic resistance, which does not ensure the transfer of stresses to the reservoir, and, therefore, does not provide the necessary amount of fracturing in the reservoir; is difficult to pump both in pipes and in formation; has a high filtrational return; is expensive due to the use of expensive imported VHR tylose reagent.

Closest to the invention is a fracturing fluid comprising the following ingredients. wt.%: CMC 1.0-2.5; chromates 1.0-3.0; lignosulfonates 0,2-0,7; salt of chloric acid 0.75-2.1; reservoir water the rest. This fluid is recommended for use in fracturing with a bottomhole temperature of 60-150 ° C.

However, this known fluid, when interacting with petroleum fluids, forms tightly removable stable emulsions in the formation, which impede the flow of oil from the reservoir into the well, which reduces the efficiency of hydraulic fracturing operations.

In addition, the known fluid provides a degree of recovery of the initial permeability of the reservoir by only 38.7-46.9%, which, under field conditions, leads to a decrease in the flow rate of the reservoir.

In addition to TorjD, a known fluid is hardly pumpable, and even with a minimum lower limit of ingredient content, its pumping capacity is only 66 cm / s, which, under field conditions, leads to technological difficulties when using this fluid.

At the same time, the known fluid has a high filtrate yield (1114 cm in 30 minutes), which in field conditions leads to the penetration of the filtrate into the reservoir and its blockage.

In addition, the composition of the known liquid includes expensive and, moreover, harmful and poisonous substances — chromates and chlorates, which lead to the pollution of groundwater, as well as dangerous for people in the process of preparing this liquid.

The purpose of the invention is to increase the efficiency of the fluid by eliminating the formation in the reservoir of labor-resistant, stable emulsions and by increasing the degree of restoration of the initial permeability of the reservoir while improving its pumpability, reducing filtrate return, maintaining low hydraulic resistance and reducing the cost of fluid,

The purpose of the invention is achieved by the fact that hydraulic fracturing fluid, including lignosulfonates, inorganic potassium salt, water-soluble polymer and formation water, additionally contains ML-80 based surfactant based on sulfonate and sulfonol 0, and as lignosulfonates , inorganic potassium salt and water-soluble preamer contains, respectively, sulfite-alcohol yeast bard (SSDB), potassium chloride and polyacrylamide 5 (PAA) in the following ratio of ingredients, wt.%;

SSDB31,72-39,76

Potassium Chloride 3.37-6.912

PAA0.05-0.12

0PAV0.03-0.15

Plastova vodaEstalnoe

To prepare 100 g of liquid, 59.88 g (50.75 ml) of formation water 5 with a density of 1180 kg / m containing 0.03 g of surfactant are poured to 31.72 g (26 ml) of SDBR with a density of 1220 kg / m, then the resulting the mixture was administered 3.37 g of KCI and 5 g of 1% PAA. The mixture is stirred with a laboratory stirrer for 30 minutes and a hydraulic fracturing fluid is prepared (run 2, Table 1) of the following composition, wt%;

Lignosulfonates (SSDB) 31.72

SAW ML-800,03

Potassium Chloride 2.27

PAA0.05

5 Plastova waterEverything

Liquids with different ingredient contents are prepared in the same way.

During laboratory tests, the density, conventional viscosity with a VBR-1 instrument, the dynamic shear stress and plastic viscosity on a VSN-3 instrument, the filtration rate on a vacuum unit with a differential pressure of 0.1 MPa in 30 minutes, are measured coefficient of core permeability recovery on the ACM core sampling equipment; The pumping ability of the fluid is measured in a vacuum unit. The assembly consists of a vacuum pump, a buffer tank, a vacuum gauge and a Buchner kit, into which a 250 cm divider is inserted. The diameter of the hole in the funnel tap is 3 mm. The funnel in the flask is secured with a rubber stopper. All parts are interconnected by a vacuum tube.

Measurement of the pumping capacity of the proposed and known fluids for hydraulic fracturing is carried out as follows.

With the faucet closed, 250 cm of the test liquid is poured into the funnel, then the pump is turned on and a vacuum is created in the flask to the required constant value, which is fixed by the vacuum gauge indication. Then open the valve funnel and simultaneously include a stopwatch. When the total fluid volume from the funnel has elapsed (at this time, the gauge needle returns to its original position), the stopwatch is stopped. The rate of fluid outflow is determined by dividing the volume of liquid. Ps this indicator is judged on the pumping ability of the liquid.,

Data on the composition and properties of the proposed and known fluids for hydraulic fracturing are given in Table 1. The data in Table 1 show that the proposed; 1 tank for hydraulic fracturing in the following ratio of ingredients, wt.%:

SSDB31,72-39,76

Potassium Chloride 3.37-6.92

PAA0.05-0.12

PA8ML 80 0.03-0.15

Plastova vodaEstalnoe

satisfies all requirements for fracturing fluids.

The data on the coefficient is restored by the scientific research institute of the initial permeability of the core after exposure to the proposed and known fluids for hydraulic fracturing and their pumping capacities are given in T.2.

The data in DS.2 shows that the coefficient of recovery of the initial permeability of the core treated with the proposed fluid is very high and amounts to 93.8-98.4%, while for known liquids it is two times lower. Consequently, after exposure to the proposed fluid the pore space of the reservoir will not be kolmat, and the well productivity will not deteriorate. ..

The pumping ability of the proposed fluid for hydraulic fracturing is high, I eo is 72.5-73.3 cm / s, i.e. close to the pumping capacity of water, for which it is equal to 73.5.

Data on technological parameters of the proposed sauces of well-known fluids for hydraulic fracturing after their interaction with petroleum fluids are given in Table 3.

The data given in t. C, show that the interaction of known liquids with oil produces stable emulsions. This is proved by the sharply decreasing filtrational output of the resulting material (in the prototype from 14.0 to 5.5 cm and an increase in plastic viscosity (from 4 to 8 mPa-s), which is characteristic of the emulsions formed. While the liquid offered has all the technological properties after its interaction with Oil, it remains practically at the initial level, i.e., no stable emulsions are formed.

  Fo rumula and 3 revolving Fluid for hydraulic fracturing, including lignosulfonates, inorganic potassium salt, water soluble polymer, and reservoir gas; that, in order to increase its efficiency at the expense of eliminating the formation of labor-producing stable emulsions in the reservoir and by increasing the degree of restoration of the initial permeability of the reservoir while simultaneously improving its recoilability, reducing filtrate return. maintaining low hydraulic resistance and reducing the cost of the fluid, it additionally contains ML-80 surfactant based on sulfonate and sulfonol, and as lignosulfonates, inorganic potassium salt and water-soluble polymer contains the corresponding sulfite alcohol yeast bard, potassium chloride and polyacrylamide in the following case Gredientov, wt.%: Sulfite-alcohol yeast bard31,72-39,76

Potassium Chloride 3.37-6.92

Polyacrylamide 0.05-0.12

The specified surface-active: substance brand ML-80 0.03-0.15, Plastova water Else

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table 2

TaO c 3

Claims (1)

Claim Hydraulic fracturing fluid, including lignosulfonates, inorganic potassium salt, is a water-soluble polymer and formation water, which is different. which, in order to increase its efficiency by eliminating the formation of hard-to-extract stable emulsions in the formation and, by increasing the degree of restoration of the initial permeability of the formation while improving its pumpability and lowering the filtrate recovery. maintaining low hydraulic resistance and reducing the cost of the liquid, it additionally contains a surfactant of the ML-80 brand based on sulfonate and sulfonic acid, and contains lignosulfonates, an inorganic salt of potassium, and a water-soluble polymer, respectively, of sulfite-alcohol yeast vinasse, potassium chloride, and polyacrylamide in the following ratio of ingredients, wt.%: Sulphite-alcohol yeast barda Potassium chloride Polyacrylamide Specified surface-active substance of the brand ML-80 Formation water 31.72-39.76 3.37-6.92 0.05-0.12 0.03-0.15, the rest Table Plastic viscosity, MPa. from | Suggested fluid | _ in 0 Midrange in ID with About Midrange ’T t- 'SO *“ 1 Known liquid | 0 - not measured Dynamic shear stress, dPa _{o o o o} o _o o o VSN-3 device rolls over 0 - not measured Filtration in 30 min, cm ³ i oh, U1L OOIOI mid in ABOUT about · <r " Conditional viscosity At V100, with I MF MF MF MF with co 'co' co'cog 86.0 3,5-45,0 Density, kg / m ³ ί SPO Yu SO СО t- СО g- with σι о о о ч — т-т-- - midrange midrange gg ~ gg * tg 1120 1172-1170 Component Content Formation water The rest The rest The rest The rest The rest The rest The rest is i o _{t- [} (PAA tt tn о fortunately with О О Т- о <- Т- το о 'о о о о о о Tylose 2.5 CMC 1.0-2.5 oh co 1 Σ MF SO t- o 1P <0 о О Т-Т- О Т- το о о о О о о о in g-  o ♦ o “Oh B Potassium chloride T- G- SO O MF MF O t- ^ s G t- α> σ> mso with h ABOUT " about ₽ * »· about 2 £ »ό Oh t- 2 in from Ф Д зНя Η 2Г = TF SO .. About MF G- G- MF <0 MF 10 WITH SO G-; G ch-t-schs0t “О>“ “СО СО СО СО СО СО СО Ч * KSSB-2 0.3 0.2-0.7 Fluid composition T- SCH WITH M-10 <0 g * · 00 About table 2 Fluid composition Initial core permeability, μm ² Core permeability recovery coefficient,% ¹ ....... H Pumping capacity, cm ³ / s Suggested fluid 2 0,0334 93.8 73.3 0.0860 98.4 5 0.0250 94.5 72.8 0.0820 9.4.9 6 0.03025 95.6 72.5 0.0770 94.8 \ Known fluid 8 0,02538 47.8 10,4 0.0660 58.9 9 0.0170 46.9 66.0 0,0669 38.7 TaOyayats * 3 p / p Test fluid Density. kg / m ³ Viol Filtration, cm ³ Dim I’m inekoenearyazh · ’shift. dpa Lmspkvskm mzhost, mPe-s 1 Liquids 2 1180 3.2 7.0 0 0.5 2 Liquid 2 + 10% oil 1180 3.2 7.0 0 05 Liquids 5 1193 3.2 4.0 05 fifteen 5 + 10% oil fluid 1193 3.3. 4.1 O.7 fifteen 3 Fluids 6 \ 1201 48.0 U 0 35 Liquids 6 + 10% oil 1200 48.0 V 0 35 4 Fluid 8 1120 86 10 N “VSN-3 device not. Liquid 8 * 10% oil 1118 98 4 is (rolls over) 5 Fluid 0 1172 3.5 14 0 4 Liquid 9 + 10% oil 1169 4.8 5.5 0