39results about How to "Good temperature resistance and shear resistance" patented technology

The invention relates to recovered fracturing fluid used in a natural gas well. The fracturing fluid comprises components of, by weight: 0.25% to 0.45% of a natural plant gum thickener, 2.0% to 3.0% of potassium chloride, 0.01% to 0.02% of a bactericide, 0.40% to 1.20% of a cleanup additive, 0.3% to 0.7% of cross-linking liquid, 0.01% to 0.025% of a pH value regulator, 0.08% to 0.2% of a gel breaker, and balance of water. During on-site construction, the fracturing fluid is adopted in fracturing construction; the liquid discharged back from the stratum is settled, and filtered; silt and mechanical impurities are removed, and the liquid is stored in a tank. When fracturing construction is carried out again, the pH value regulator is added to the liquid, such that a gel is formed again, andthe gel can be used. With the recovered fracturing fluid provided by the invention, waste liquid discharging and processing can be reduced, a large amount of water can be saved, liquid blending time can be saved, and construction period can be shortened.

The invention discloses a single-component full-function fracturing fluid additive and a preparation process thereof. The process comprises the following steps: mixing ethylene glycol, isopropanol, 1-butanol, 1-hexanol and 1-octanol, and conducting heating to uniformly disperse the mixture to obtain a water-based dispersant; adding a high-molecular polymer thickening agent and an auxiliary agent into a water-based dispersing agent, wherein the auxiliary agent is one or more of a clay stabilizer, a discharge aiding agent, a drag reducer, an anti-emulsifying agent, a filtrate reducer, a corrosion inhibitor and a sterilizing agent; conducting stirring at a high speed to obtain suspension; and slowly stirring the suspension at a low speed, conducting cooling, and collecting a suspension sample when the temperature of the suspension is reduced to room temperature. The additive has the characteristics of good temperature resistance, shearing resistance, salt resistance, sand suspension and the like. The problems that an existing fracturing fluid system is serious in stratum pollution, difficult to dissolve, single in function, poor in performance and the like are solved, and the additive has the advantages of being good in use performance, environmentally friendly, capable of saving energy and reducing consumption and can be used as a clean and environment-friendly single-component type full-function fracturing fluid additive.

The invention relates to clear fracturing fluid, which is used for fracturing treatment of a hypotonic and water-sensitive reservoir, and comprises the following components in percentage by weight: 0.5-5 percent of dimethyl octadecyl ethoxy quaternary ammonium nitrate; 0.2-2 percent of sulfosalicylic acid triethanolamine ester; 0.5-2 percent of potassium chloride; and the balance of water, wherein the weight percentage of the components is a hundred percent. A preparation method comprises the following steps of: adding clear water into a mixing liquid tank, adding the potassium chloride and the sulfosalicylic acid triethanolamine ester under a stirring condition, uniformly stirring, adding the dimethyl octadecyl ethoxy quaternary ammonium nitrate, and stirring for 15 minutes after adding the materials, so that the concentration or the viscosity of liquid in the upper part and the lower part of the tank is uniform. The clear fracturing fluid has the effects that: the clear fracturing fluid is suitable for fracturing the reservoir at the temperature of 10 DEG C-110 DEG C, the damage caused by residues of the fracturing liquid and reservoir water sensitivity can be reduced, and the crude output is improved.

The invention relates to a carboxymethyl hydroxypropyl guanidine gum fracturing fluid which is used for fracturing reformation of a high-temperature and low-permeability reservoir. The carboxymethyl hydroxypropyl guanidine gum fracturing fluid comprises the components by weight percent: 0.25-0.6% of carboxymethyl hydroxypropyl guanidine gum, 0.2-0.6% of cross-linking agent, 0.2-0.4% of cross-linking regulator, 0.5-1% of clay stabilizer, 0.05-0.1% of bactericidal preservative, 0.2-0.5% of discharge aiding agent, 0.0001-0.15% of ammonium persulfate and the balance of water. A preparation method of the fracturing fluid comprises the steps of: adding clear water into a large tank, adding the carboxymethyl hydroxypropyl guanidine gum into the large tank under the stirring condition, and then sequentially adding the clay stabilizer, the discharge aiding agent, the cross-linking regulator and the bactericidal preservative into the large tank; and stirring for 10 minutes until the concentration or the viscosity of liquid at the upper part and the lower part of the large tank is uniform and consistent. During fracturing construction, the cross-linking agent and gel breaker are added into the large tank according to the requirement. The carboxymethyl hydroxypropyl guanidine gum fracturing fluid has the effects of being suitable for the reservoir temperature of 80-200DEG C, reducing the residue of the fracturing fluid and the construction friction, and meeting the demand of fracturing reformation of the high-temperature and low-permeability reservoir.

The invention relates to a fracturing fluid, which includes a densifier I, a densifier II, a clay stabilizer, a bactericide, a pH conditioning agent, a cross-linking agent, a gel breaker and water, wherein the densifier I is nonionic polyacrylamide, and the densifier II is hydroxyethyl carboxymethyl cellulose. The invention further relates to a preparation method of the fracturing fluid. The preparation method includes: (1) during stirring, adding the densifier I and the densifier II to water, then adding the clay stabilizer, the bactericide, and the pH conditioning agent, performing uniform stirring to obtain an original glue solution, and performing standing for 3-5 h; and (2) adding the gel breaker, and then adding the cross-linking agent to obtain the fracturing fluid. The densifier I is nonionic polyacrylamide, and the densifier II is hydroxyethyl carboxymethyl cellulose. Since the fracturing fluid includes two densifiers of nonionic polyacrylamide and hydroxyethyl carboxymethyl cellulose, the fracturing fluid is small in densifier consumption, good in temperature-resistant shearing resistance, complete in gel breaking, low in residue content, cheap and available in raw materials, and low in cost.

At present, more than 90 percent of fracturing fluids used in the fracturing improvement of oil and gas fields are water-based fracturing fluids with water as dispersion medium, and as a result, for gas reservoirs with low formation pressure, low permeability and strong water-locking characteristic, particularly highly water-sensitive gas reservoirs, the difficulty of fluid flowback can be easily caused because the formation pressure coefficient is greatly smaller than the pressure coefficient of water in a shaft; and formation pores can be easily blocked due to the water-locking effect of formations to cause the failure of fracturing improvement. Because low-molecular weight alcohol, particularly methanol, has a lot of excellent physical and chemical properties, the low-molecular weight alcohol can be used in the improvement of low-pressure, water-sensitive formations for stimulation, and compared with conventional water-based fracturing fluids, methanol-based fracturing fluid has the characteristics of low surface tension, good water-solubility, low freezing point, high steam, high compatibility with formation rocks and the like. The invention relates to a thickening agent for methanol-based fracturing fluid, which is used in the fracturing stimulation process of natural gas wells or oil wells; because methanol and water can be formed into any proportions of mixtures, the methanol-based fracturing fluid can absorb the water constrained by water-locking formations to the maximum limit after entering the formations, and moreover, as the fracturing fluid is drained out of the ground, the water locking of the formations is released, which is favorable for the flowback of the fluid.

The invention discloses a multi-lithologic fracturing crack test method, which includes the following steps: (1) rock matrix production: according to different rock mechanical parameters, the mass ratios of cement, quartz sand and water are prepared to simulate shale respectively. , cuboid sheet of coal rock and limestone; (2) simulation of fracture system: in the process of making rock sheet, the pre-set paper sheets are used to simulate coal rock, shale bedding and coal rock cleavage; (3) sample combination; ( 4) Sample drilling: According to the characteristics of the horizontal well and vertical well, drill a counterbore with a length of 16 cm and a diameter of 14 mm on the surface of the sample along the direction parallel or perpendicular to the bedding, cement the simulated wellbore, and reserve the lower part. 2cm open-hole section; (5) select the type of proppant; (6) perform the Gaza process; (7) evaluate the conductivity of the proppant. Therefore, the present invention is a simulation method capable of quantitatively and accurately predicting the true propagation trajectory of the staged fracturing fractures in horizontal wells.

The invention provides a low-damage nitrogen foam fracturing liquid for a weak water-bearing coal-bed gas well and a preparation method thereof. The gas phase of the foam fracturing liquid is nitrogen, the liquid phase of the foam fracturing liquid is an additive solution, and the foam mass is 60 to 80 percent. The foam fracturing liquid is prepared from the following components in percentage by mass: 0.5 to 1.5 percent of a foaming agent, 0.3 to 0.7 percent of a foam stabilizing agent, 0.2 to 0.6 percent of a clay stabilizing agent, 0.1 to 1.0 percent of an auxiliary desorption agent and 96.2to 98.9 percent of water. The foaming agent is mainly an anionic surfactant; the foam stabilizing agent is mainly an amphoteric surfactant; the clay stabilizing agent is mainly an organic solvent; the auxiliary desorption agent is mainly a fluorocarbon surfactant. The foam fracturing liquid does not contain a macromolecular additive, has good temperature resistance and shearing resistance, high sand suspending capacity, good coal powder dispersing performance and negative damage to a coal rock core, and has a great significance to efficient development of weak water-bearing coal-bed gas and reservoir protection.