36results about How to "Improve flowback performance" patented technology

The invention discloses a formula and a preparation method suitable for preparing fracturing fluid from continental facies shale gas well fracturing flow-back fluid treatment water, belonging to the technical field of oilfield chemistry. The formula for preparing the fracturing fluid from the continental facies shale gas well fracturing flow-back fluid treatment water is provided aiming at the deficiencies existing in the prior art. The formula consists of base fluid and a cross-linking agent, wherein the cross-linking agent is an anti-temperature mineralization-degree-resistant cross-linking agent, and the formula comprises 0.4%-0.6% of cross-linking agent and the balance of base fluid; the base fluid consists of the following components in percentage by mass: 0.4%-0.45% percent of hydroxypropylguar gum, 0.3%-0.5% of gas well clean up additive, 1%-2% of stabilizer, 0.1%-0.15% of bactericide, 0.1%-0.2% of modifier, 0.03%-0.05% of antisludging agent, 0.6%-0.8% of gel breaker and the balance of the continental facies shale gas well fracturing flow-back fluid treatment water. The cyclic utilization of the continental facies shale gas well fracturing flow-back fluid treatment water is realized through the formula of the fracturing fluid, and the prepared fracturing fluid has good sand-carrying property.

The invention discloses a slippery water fracturing fluid with ultra-low interfacial tension with crude oil after degradation. The slippery water fracturing fluid is prepared from an ultra-low interfacial tension drag reducer, a demulsify-cleanup additive, a clay stabilizer and a degrading agent. A preparation method of the slippery water fracturing fluid comprises steps as follows: 0.02%-0.10% in percentage by mass of the ultra-low interfacial tension drag reducer, 0.1%-0.2% in percentage by mass of the demulsify-cleanup additive and 0.3% in percentage by mass of the clay stabilizer are added to every ton of water, the agents are mixed to form a homogeneous solution, and 0.08% of the degradation agent is added from a mixing tank of blending equipment during construction. Additives of the slippery water fracturing fluid are all liquid phase, and the slippery water fracturing fluid can be quickly dispersed in water, have good salt tolerance, are not easily affected by the content of bacteria in a fluid preparation solution and have a stable drag reduction effect under the construction displacement of 6-20 m<3>/min; when applied to improvement of low-permeability oil and gas reservoirs, the slippery water fracturing fluid can reduce the interfacial tension between a gel breaking liquid and crude oil and reduce string and construction friction, helps production of the crude oil, increases of the yield of the crude oil and can be prepared repeatedly from backflow fracturing fluids.

The invention relates to ampholytic surfactant fracturing fluid and a preparation method thereof. The ampholytic surfactant fracturing fluid comprises the following components in percentage by mass: 3 to 5 percent of ampholytic surfactant, 0.5 to 1 percent of anionic surfactant, 2 to 4 percent of inorganic salt, 0.3 to 0.5 percent of alcohol with low molecular weight, 0 to 5 percent of pH value regulator, 0.5 percent of clay stabilizer and the balance of water. The preparation method comprises the following steps of: adding the ampholytic surfactant, the anionic surfactant, the alcohol with low molecular weight, the pH value regulator, and the clay stabilizer into water, stirring for 5 to 10 minutes to obtain uniform and stable suspension, adding the inorganic salt, and stirring for 1 to 2 minutes to obtain fluid with high visco-elasticity. The ampholytic surfactant fracturing fluid is used for fracturing of an oil and gas field of which the formation temperature is 60 to 80 DEG C, residues are avoided after gel breaking, and a stratum is not damaged.

The invention relates to a preparation method of a fracturing supercritical carbon dioxide thickener containing a siloxane polymer. The method comprises the steps: carrying out a reflux reaction on anaminopropyl alkoxy silane hydrolysis product, tetravinyl tetramethylcyelo tetrasiloxane and other cyclosiloxane under the catalysis of an alkali to prepare aminopropyl-terminated vinyl side chain modified polydimethylsiloxane; then, carrying out an acylchloride reaction on the aminopropyl-terminated vinyl side chain modified polydimethylsiloxane and aroyl chloride to prepare an aroylamino-terminated side chain modified siloxane polymer; dropwise adding an organic solvent solution of chloroplatinic acid to make the aroylamino-terminated side chain modified siloxane polymer react with hydrosiloxane to obtain a product. The preparation method is high in monomer synthesis efficiency, the siloxane polymer serving as phenyl and acylamino in the fracturing supercritical carbon dioxide thickenerproduct is capable of improving the thickening effect, and when the dosage of the product is relatively low, the thickening performance is good, and the pollution to underground water and surface water of a stratum is reduced.

The invention discloses an energy enhancing steering acid liquid system, which comprises 615 parts of hydrochloric acid, 10 to 20 parts of corrosion inhibitors, 30 to 50 parts of steering agents, 10 to 20 parts of foam boosters and 10 to 20 parts of iron ion stabilizing agents. The system has the advantages that liquid has better automatic steering low-seepage storage layers, the goals of uniformly distributing acid and reforming the storage layers with poor storage seepage conditions are reached, simultaneously, the static liquid post pressure of liquid in a well tube is also reduced, and the liquid return and discharge capability after the construction is improved.

The invention discloses a scale remover for a water injection well, and a preparation method and an application of the scale remover, and belongs to the field of oil field development. The scale remover comprises the following components, by mass, 25-40% of a scale-dissolving agent, 3-6% of a dispersant, 3-6% of a corrosion inhibitor, 3-6% of a cleanup additive, and 1-3% of a suspending agent, with the balance being water. The scale-dissolving agent is a hydrochloric acid solution having a concentration of 25-37%; the dispersant is selected from at least one of carboxymethyl cellulose, sodium dodecyl sulfate, and 1-methylpentanol; the corrosion inhibitor is chloridized benzylquinoline quaternary ammonium salt; the cleanup additive is selected from at least one of dodecylpyridinium bromide, hexadecylpyridinium bromide, and octadecylpyridinium bromide; and the suspending agent is lignin. The scale remover can deeply remove scale, has a corrosion inhibition function, is easy to flow back, and doesn't cause secondary pollution on the stratum.

The invention relates to a synthetic method of a slippery water fracturing degradable diverting agent. Lactic acid (LA) is a monomer, stannous octoate (Sn (Oct) )(2) is used as an initiator, and polylactic acid (PLA) with carboxyl at the tail end is synthesized under the protection of nitrogen; tert-butyl acrylate (TBA) and 2-acrylamide-2-methylpropanesulfonic acid (AMPS) are used as functional monomers, carboxylic azo compound (4,4'-azobis(4-cyano valeric acid)) is used as an initiator, and oligomer (AMPS-TBA) with carboxyl group at the tail end is synthesized under the protection of nitrogen; the polylactic acid (PLA) with carboxyl at the tail end, the oligomer (AMPS-TBA) with carboxyl group at the tail end and a starch solution are mixed, graft copolymerization is performed by using concentrated sulfuric acid as a catalyst; the grafted copolymer product is granulated and dried to obtain solid particles which are the slippery water fracturing degradable diverting agent. The prepared slippery water fracturing degradable temporary plugging diverting agent has the advantages of being easy to degrade, good in flowback performance, high in temporary plugging strength and environment-friendly in raw materials.

The invention relates to a cationic type gelled acid thickener. The gelled acid thickener is a copolymer comprising four monomers of acrylamide, a phosphorus-containing cationic monomer, dimethyl diallyl ammonium chloride and 2-acrylamido-2-methyl propanesulfonic acid. The invention also relates to a preparation method of the cationic type gelled acid thickener; the method selects the high-temperature-resistant phosphorus-containing cationic monomer, and adopts 'a two-step temperature control method' for preparing the gelled acid thickener, to improve the molecular weight of the product; the prepared cationic type gelled acid thickener has the advantages of short swelling time, good temperature resistant performance, high residual acid flow-back efficiency, little damage to a reservoir stratum and the like, and can meet the acidizing fracturing construction requirements on a 140-DEG C reservoir stratum.

The invention discloses a fast drilling bridge plug made of a composite material, belonging to the technical field of oil and gas field exploitation. The fast drilling bridge plug comprises a shaft lever made of a epoxy glass fiber composite material, wherein an end shaft is arranged on the outer surface of the bottom end of the shaft lever; a plug is arranged at the axis of the top end of the shaft lever; the plug and the shaft lever are sealed by a sealing ring; a first slip bowl and a second slip bowl are fixed on the shaft lever; the sealing ring is mounted between the first slip bowl and the second slip bowl; transition tiles are arranged among the sealing ring and the first slip bowl as well as between the sealing ring and the second slip bowl; the first slip bowl is connected with one end of a first slip made of a metal material; the other end of the first slip is connected with a thrust ring; the second slip bowl is connected with one end of a second slip made of a metal material; and the other end of the second slip is connected with the end shaft. According to the bridge plug disclosed by the invention, the problems in the prior art that drill beating and jamming of a drilling tool easily occur during bridge plug drilling, the bridge plug chips cannot flow back easily and the construction efficiency is low are solved.

The embodiment of the invention provides a soaking time determination method and a soaking time determination device. The method comprises the following steps: obtaining the type information of a fracturing fluid of a target well, and obtaining the gel breaking viscosity of the fracturing fluid according to the type information of the fracturing fluid; according to the fracturing pump injection program of the target well, the single-fracture fracturing fluid dosage is obtained; obtaining invasion area thickness and invasion area permeability according to the logging data of the target well; and the soaking time of the target well is determined according to the fracturing fluid gel breaking viscosity, the single-slit fracturing fluid dosage, the invasion area thickness and the invasion areapermeability. After the soaking time determined by the embodiment of the invention is adopted for soaking, the flowback rate of the propping agent can be effectively reduced, a better flowback effectcan be achieved, and the flow conductivity of cracks is ensured.

The invention relates to an acidic cross-linking fracturing liquid. The acidic cross-linking fracturing liquid is characterized in that the acidic cross-linking fracturing liquid is formed by a solution A and a solution B, the volume ratio of the solution A to the solution B is 100:0.5-2.0, the solution A comprises 0.5-1.0 part by weight of a modified starch thickening agent, 0.5-0.8 parts by weight of a foaming agent, 0.5-1.0 part by weight of a clay stabilizer, 0.5-0.8 parts by weight of a cleanup additive, 0.005-0.5 parts by weight of a gel breaker, and 96-98 parts by weight of water, and the solution B comprises 0.5-1.0 part by weight of a cross-linking agent and 99-99.5 parts by weight of water. The acidic cross-linking fracturing liquid has good rheology and gel breaking performances, satisfies requirements of long-crack and high-sand-ratio construction and CO2 foam fracturing construction technologies, has a low damage to the permeability of a rock core, has a good reservoir stratum adaptability, can effectively inhibit the clay expansion, and has an excellent gel breaking performance and low residues.

The invention provides seawater-based fracturing fluid as well as a preparation method and application thereof. The seawater-based fracturing fluid comprises a base fluid and cross-linking agent accounting for 0.1 to 0.14 percent of the weight of the base fluid; the base fluid comprises a seawater-based fracturing fluid thickening agent, a chelating agent, a high-temperature stabilizer, an anti-swelling agent, a drainage aid, a performance regulator and seawater, and the seawater-based fracturing fluid thickening agent accounts for 0.8 to 1.2 percent of the weight of the base fluid; and the cross-linking agent is alkyl sulfonate containing 8 to 12 carbon atoms. The base fluid and the cross-linking agent are stirred and mixed at a room temperature to form viscose and elastic fluid, i.e. theseawater-based fracturing fluid. The seawater-based fracturing fluid provided by the invention has the advantages of good sand carrying property, high temperature resistance, no heavy metal elements,low content of gel breaking residue after gel breaking and the like by carrying out the physical cross-linking by virtue of multi-element association effect, and is particularly suitable for the fracturing construction of marine high-temperature oil and gas reservoirs.

The invention provides a viscoelastic acid-resisting clean fracturing fluid. The acid-resisting clean fracturing fluid is suitable for a stratum of 60-100 DEG C, and the acid-resisting clean fracturing fluid is characterized by comprising, by mass, 0.2-0.4% of a hydrophobic associating polymer thickening agent, 2-3% of a viscoelastic surface active agent, 3-6% of inorganic salt, 0.02-0.2% of a gelbreaker and the balance water. The preparation method comprises the steps of (1), preparation of a base solution, wherein according to the ratio in the formula, the hydrophobic associating polymer thickening agent is prepared into powder and carried by water via negative pressure into a liquid preparation tank, stirring is conducted for about 20-40 minutes, so that the hydrophobic associating polymer thickening agent is swelled, the inorganic salt is added, stirring is conducted to make the inorganic salt completely dissolved, and standing is conducted for 2-3 hours for use; (2), preparationof a surface active agent crosslinking solution, wherein according to the ratio in the formula, the surface active agent and the water are added, and stirring is conducted until the active agent is dissolved completely; (3), preparation of the viscoelastic acid-resisting clean fracturing fluid, wherein the prepared base solution and the prepared surface active agent crosslinking solution are obtained, prepared in a weight ratio of (8-12):1 and significantly stirred to be uniform to obtain the viscoelastic acid-resisting clean fracturing fluid. After 1-3% of HCl is added into a fracturing fluidsystem, the viscosity is reduced by 5% or below.

The invention discloses self-crosslinking high-sand-carrying cleaning quick water. The quick water is prepared in the mode that a drag reducer is added into water; the drag reducer is a polymer emulsion which is prepared in the mode that an internal phase solution and an external phase solution generate a double-phase emulsion polymerization reaction under the effect of an initiator; the externalphase solution is prepared from the components of polyester, an environment-friendly solvent and a cross-linking agent; and the internal phase solution is prepared from the components of 2-acrylamido-2-methylpropane sulfonic acid, organic amine and water. The preparation steps comprise: (1) the polyester, the environment-friendly solvent and the cross-linking agent are mixed to obtain the externalphase solution; (2) the water, the 2-acrylamido-2-methylpropane sulfonic acid and the organic amine are mixed to obtain the internal phase solution; and (3) the external phase solution is placed in awater bath of 30-40 DEG C, the internal phase solution is added, after nitrogen is introduced for deoxygenation, the initiator is added, a reactor is sealed, a thermostatic reaction is conducted for4-5 h at 80 DEG C, and the self-crosslinking high-sand-carrying cleaning quick water is obtained. The quick water integrates various functions, can be quickly dissolved and efficiently reduce drag, and has the functions of sterilization, flow back assistance and clay stability synergy.