66results about How to "Improve flowback rate" patented technology

The invention discloses a shale gas well CO2 and slickwater mixing fracturing technology, and relates to the technical field of shale gas exploiting, in particular to the mixing fracturing technology by adopting CO2 and slickwater. In the construction process, a fracturing truck, a fracturing blender truck, a CO2 tank truck, a CO2 pump truck, a measuring truck, a fracturing manifold truck, an acid tank, propping agents and a liquid storage pot group need to be prepared, the fracturing manifold truck is provided with a low-pressure manifold and a high-pressure manifold, and the measuring truck is provided with a monitoring instrument, and the technology is characterized by comprising seven steps of doing well site planning, pressure testing, acid liquid processing, CO2 fracturing construction, slickwater fracturing construction, well closing after fracturing, and flow opening and flowback after fracturing. The shale gas well CO2 and slickwater mixing fracturing technology has the advantage that the shale gas exploiting method which is low in cost, low in relative construction difficulty, small in damage to a shale gas reservoir stratum and efficient is achieved.

The invention relates to a fracturing fluid system used in an oil and gas field, in particular to a fracturing fluid system of CO2 cleaning foam. The fracturing fluid system comprises the following components in percentage by weight: 0.3-0.8 percent of water-soluble hydrophobic association polymer, 0.25-0.55 percent of rheological auxiliary agent, 0.5-3.0 percent of clay stabilizer, 0.1-0.5 percent of foaming agent, 0.01-0.2 percent of gel breaker, 30.0-80.0 percent of liquid CO2 and the balance of water. Compared with the prior art, in the fracturing fluid system of the CO2 cleaning foam, a cross-linking agent is not needed, the foamability is good, the foam stability is high, the sand-carrying capability is strong, gel breaking is easy to control, no residue is generated after gel breaking, the superficial/interfacial tension of gel-breaking liquid is low, and the damage to the formation is less, and therefore, the fracturing fluid system can be used for fracturing modification of hypoisotonic, low-pressure and water-sensitive storage layers at the temperature of 60-140 DEG C.

The invention provides high-temperature resistant CO2 foam cleaning and associated fracturing fluid and a preparation method and application thereof. The high-temperature resistant CO2 foam cleaning and associated fracturing fluid comprises a fracturing fluid base solution, a cross-linking agent, a gel breaker and liquid CO2, wherein the cross-linking agent and the gel breaker account for 0.3%-0.8% and 0-0.05% of the fracturing fluid base solution in parts by weight separately; and the liquid CO2 accounts for 30%-70% of total volume of the CO2 foam cleaning and associated fracturing fluid. The high-temperature resistant CO2 foam cleaning and associated fracturing fluid provided by the invention has the characteristics of being few in additive types, simple in preparation, controllable in crosslinking, low in residue, low in damage, low in friction, high in foaming efficiency, high in flowback rate and resistant to high temperature.

The invention provides an immovable string hydraulic sandblasting fracture annulus pressure control method for a gas field horizontal well, and belongs to the technical field of gas field horizontal well sectional improvement. An immovable string hydraulic sandblasting fracture technique string of the gas field horizontal well is laid in the gas field horizontal well, and ejectors are aligned to planned improvement positions; a throttle valve is installed at a wellhead sleeving and releasing outlet, and a sleeving and releasing pipeline is connected into a slurry pond; sandblasting and perforation are carried out on target sections according to construction design, an annulus is opened during sandblasting and perforation, and annulus pressure is controlled through the throttle valve; after perforation, displacement is increased, jet flow pressurization is improved, the annulus pressure is adjusted through the throttle valve, a stratum is pressed open and then a sleeve gate is closed for main fracture construction, and liquid nitrogen is injected in the whole process of main fracture construction of each section; a next layer hydraulic sandblasting fracture tool is opened in a ball throwing mode for next layer perforation and fracture construction; after pressing, the aims that liquid is quickly discharged, the flowback rate is increased, and construction risk is lowered are achieved.

The invention belongs to the technical field of oil exploitation, and relates to a refracturing modification process for a low-permeability and low-yield gas well, in particular to a CO2 refracturing process technology for a low-permeability gas well. The CO2 refracturing process technology is used for performing secondary fracturing construction for an implemented well, comprises analysis and optimization before fracturing and fracturing construction, and is characterized in that the analysis and optimization before fracturing comprises fracturing failure analysis, fracturing material optimization and construction parameter optimization, and the specific process technology is implemented according to steps of fracturing failure analysis, fracturing material optimization, construction parameter optimization and refracturing construction. According to the CO2 refracturing process technology for the low-permeability gas well, a CO2 foam fracturing technology and low-damage cleaning fracturing liquid are used for performing a modification test for a low-yield gas well by analyzing a reservoir, the flowback rate of the fracturing liquid and the yield of the low-yield gas well are increased effectively, and damage to the reservoir is effectively reduced.

The invention discloses a surfactant complex-based high temperature-resistant solvent. The surfactant complex-based high temperature-resistant solvent is used for unconventional energy thickened oil steam-injection thermal recovery and through the surfactant complex-based high temperature-resistant solvent, a steam-chemical assistant combined exploitation method is formed. The surfactant complex-based high temperature-resistant solvent comprises a dispersant, a surfactant complex and an inorganic salt, and concretely, the surfactant complex-based high temperature-resistant solvent comprises, by mass, 5-10 parts of the dispersant, 10-30 parts of the surfactant complex, 5-10 parts of the inorganic salt and 80-50 parts of water. Through compounding of a fluorocarbon surfactant and a hydrocarbon surfactant, the surfactant complex-based high temperature-resistant solvent can resist a temperature of 300 DEG C and can improve steam transmission efficiency and stripping, viscosity reduction and displacement effects on thickened oil in thickened oil steam-injection recovery and especially in thickened oil steam assisted gravity drainage (SAGD).

The invention discloses a quick gel breaking process for intermediate and low temperate oil gas well fracturing fluid, and the process at least comprises the following steps: 1) adding a sufficient amount of gel breaking agent in a pre-loading liquid stage; 2) lowering the use concentration of a crosslinking agent in the construction field to form weak crosslinking or under crosslinking fracturing fluid gel; and 3) in the later stage of a sand-carrying agent step, i.e., when a sand adding step is about to finish, adding a gel breaking agent into well fracturing fluid in a tail chase wedge shape. The quick gel breaking process has the following advantages: (1) the water base fracturing fluid is quick, the gel is thoroughly broken, and the flowback rate is high; (2) the gel breaking process is simple, is easy to master and is convenient to operate on site; (3) the gel breaking process is wide in applicable range, is suitable for the common guar gum fracturing fluid system and is also suitable for the water base polymer fracturing fluid system of other gel breaking agents; and (4) the gel breaking process can be used for intermediate and low temperate oil gas well fracturing at the temperature of 20-60DEG C.

The invention relates to a fluoride-free cleanup additive used for acidifying, which is composed of a main agent, a reinforcing agent, a cosolvent and water. the main agent is alkyl trimethyl ammonium bromide or alkyl bromid pyridine, wherein the alkyl can be dodecyl, cetyl or octadecyl, the main agent accounts for 20-50% of the cleanup additive by weight percentage, the reinforcing agent is fatty alcohol polyoxyethylene ether, dihydroxyethyl dodecyl amide or cocamidopropyl dimethyl betaine, the reinforcing agent accounts for 1-10% of the cleanup additive by weight percentage, the cosolvent is a mixture of one or more of methanol, ethanol or glycol, the cosolvent accounts for 5-25% of the cleanup additive by weight percentage, and the balance is water. The cleanup additive is capable of effectively reducing the capillary force in stratum, rapidly discharging the residual acid liquid out of the stratum and reducing the damage to the stratum.

The invention discloses a high-temperature gas well and horizontal well drilling fluid and a completion fluid containing the same. On the basis of an original polymer sulfonated water-base drilling fluid, an acid soluble material is added to achieving weighing so as to serve as the completion fluid, the completion fluid is higher in mud-cake acid solubility and flowback rate and good in reservoir bed protective capability. The phenomena that in the later period of well completion test process, the continuous high-temperature resistant stability is poor and the probability of high-temperature degradation is high are avoided, and the problems that the later-period test result accuracy and the productivity discovery are seriously influenced, and tool blockage and accidents are easily caused are solved. The high-temperature gas well and horizontal well drilling fluid consists of a base fluid and a heavy weight additive, wherein the base fluid comprises water, a thickening agent, drilling Bentonite, an inhibiter, a plugging agent, a fluid loss reducer and a lubricant; the heavy weight additive is barite. The high-temperature gas well and horizontal well completion fluid comprises the base fluid and the heavy weight additive, wherein the base fluid is the original drilling fluid; the heavy weight additive is an acid soluble material.

The invention provides oil and gas field fracturing fluid, an oil and gas field well cementation agent and an oil and gas field fracturing temporary plugging agent, which contain PVA (Polyvinyl Alcohol) fibers. The PVA fibers are papered from polyvinyl alcohol with the polymerization degree of 1000 to 3000 and the alcoholysis degree of 80 mole percent to 99.5 mole percent through spinning; the hydroformylation degree eta of the PVA fibers is 25 percent to 35 percent and Rp is 120 DEG C to 180 DEG C. The PVA fibers have the monofilament density of 1.0dtex to 1.8dtex at normal temperature and have the elongation at break of 10 percent to 25 percent; the slenderness ratio of the fibers is 200 to 600 and the real density of the fibers is 0.8g/cm<3> to 1.4g/cm<3>. The yield increasing range of the oil and gas field can reach 30 percent to 50 percent; the strength and toughness of the well cementation agent are remarkably improved and the well cementation agent can also have an anti-leakage effect; when being used in the fractured oil and gas field, the oil and gas field fracturing temporary plugging agent aims at plugging old cracks and breaking new cracks; when the fracturing temporary plugging agent is used, the pressure is raised by 6MPA or above and the yield of the oil and gas field is improved by two times or above.

The invention provides a gas-producing system capable of improving permeability of a tight oil reservoir and application thereof, belonging to the technical field of oilfield development. The gas-producing system comprises a microcapsule and hydrochloric acid; the microcapsule uses a mixture of urea and sodium nitrite as a core material and a mixture of azodiisobutyronitrile, styrene, methyl methacrylate and methacrylic acid as a capsule dressing. In operation, nitrite and the microcapsule are injected into a stratum to a predetermined depth; and the microcapsule undergoes corrosion under stratum conditions and chemically reacts with hydrochloric acid to produce a great amount of gas and release a great amount of heat, so local high pressure is formed in a predetermined part. According to the invention, effective seepage channels of difficult-to-produce reserves such as an ultralow-permeability oil reservoir and the tight oil reservoir are increased so as to improve permeability, increase local energy of reservoirs and the flowback rate of raffinate, and reduce reservoir contamination, so the purpose of improving the recovery efficiency of the difficult-to-produce reserves is achieved.

The invention discloses a carbon dioxide acid fracturing method for a low permeability heterogeneous carbonate gas reservoir. The carbon dioxide acid fracturing method comprises the following steps that (1) CO2 tank trucks, a CO2 pump truck and fracturing trucks A are connected into a wellhead in series; (2) liquid tanks, acid tanks A and acid tanks B are directly connected with a low pressure manifold; (3) the low pressure manifold, a sand mixing truck, fracturing trucks B and a high pressure manifold are connected into the wellhead in series; (4) resistance reducing acid is subjected to pumpinjection with the displacement of 1.0-1.5m<3>/min; (5) CO2 is subjected to pump injection with the displacement of 1.5-3.0m<3>/min; (6) slickwater is subjected to pump injection with the displacement of 3.0-8.0m<3>/min; (7) the resistance reducing acid is subjected to pump injection with the displacement of 3.0-8.0m<3>/min; (8) steering acid is subjected to pump injection with the displacement of 2.0-6.0m<3>/min; (9) the steps (6)-(8) are repeated for 0-2 times, and the steps(6)-(7) are repeated for 1 time; and (10) the slickwater is subjected to pump injection. According to the carbon dioxide acid fracturing method, the acid fracturing effect can be improved, and the daily gas production quantity is increased.

The invention provides a chemical-heat-generation efficient gel breaking method used in an oil-gas well fracturing process and belongs to the field of oil exploitation. The method includes: in a hydrofracturing pumping process, adding a heat-generation chemical agent into a mixture of fracturing fluid and a gel breaking agent which are on the way of being pumped in; when sand adding is completed for replacement, continuing adding the heat-generation chemical agent. Temperature of gel breaking reaction between the gel breaking agent and a thickener can be increased, the fracturing fluid can bepromoted to realize efficient gel breaking, and viscous damage of the fracturing fluid can be reduced.

The invention discloses a polyhydroxy thickener and a high-temperature-resistant alcohol-based fracturing fluid system. The polyhydroxy thickening agent is formed by copolymerizing three monomers, namely acrylamide, N-vinylpyrrolidone and N-acrylamide propyl-N,N,N-dimethyl hydroxyethyl ammonium chloride, in an aqueous solution; and based on the total mass of the monomers, the mass ratios of acrylamide, N-vinylpyrrolidone and N-acrylamide propyl-N,N,N-dimethyl hydroxyethyl ammonium chloride are 40-85%, 5-35% and 3-25%, respectively. The high-temperature-resistant alcohol-based fracturing fluidsystem is prepared from the following raw materials: the polyhydroxy thickener, a composite cross-linking agent, a regulator, high-flash-point alcohol and water. According to the alcohol-based fracturing fluid system disclosed by the invention, the polyhydroxy thickening agent is introduced, so the alcohol-based fracturing fluid system has relatively high temperature resistance and shearing resistance, and can resist a temperature of 160 DEG C or above; by using the high-flash-point alcohol, the fracturing system is safer; and an alcohol/water ratio can be increased to 60% or above, even an anhydrous system with the alcohol/water ratio of 100% can be realized, so the fracturing fluid system has the advantages of high flowback rate, small stratum damage, safety, environment friendliness andthe like.

The invention discloses an organic acid system for acidification transformation of a carbonate reservoir and a preparation method. The organic acid system comprises the following components in percentage by mass: 45-60% of an organic acid liquid, 0.3-2% of a corrosion inhibitor, 0.2-1% of EDTA (ethylene diamine tetraacetic acid), 0.03-1.5% of a slow-speed additive, 0.03-1.5% of an iron ion stabilizer, 0.1-1% of a discharge aiding agent and the balance of water. With the combination of the corrosion inhibitor and other components, the system is capable of preventing corrosion under a strong acid condition, acidification of pipeline equipment can be retarded, corrosion of equipment and tubes can be reduced, the reaction velocity of acidic rock can be reduced, the length of an acid etching crack can be increased, and thus an effect of deep acidification transformation can be achieved.

The invention provides a drilling, jam releasing and fracturing integrated device and method for a soft coal seam. According to the device, a drill rod is assembled on a drilling machine, a jet flow drill bit is installed at the outlet end of the drill rod, and the inlet end of the drill rod is connected with an outlet of a low-temperature pump; outlets of a plurality of first liquid nitrogen tanks in the first set of liquid nitrogen tank group are connected with an inlet of a low-temperature pump through a first nitrogen supply pipeline; outlets of a plurality of second liquid nitrogen tanks in the second liquid nitrogen tank group are connected with the main nitrogen supply pipeline through a second nitrogen supply pipeline; a heater is arranged at the bottom of the second liquid nitrogen tank. The method comprises the steps of determining a coal seam drilling position and an anti-reflection transformation area; arranging a drilling, jam releasing and fracturing integrated device in the rock roadway; liquid nitrogen output by the first set of liquid nitrogen tank group is pressurized by a low-temperature pump and then is conveyed into a jet flow drill bit, and formed high-speed liquid nitrogen jet flow acts on a coal seam; and blocking the inlet of the drill hole, fracturing the coal seam by using high-pressure fluid generated by liquid nitrogen phase change, and forming cracks in the coal seam. By means of the device and method, drilling, jam releasing and fracturing operation can be integrally achieved.

The invention relates to the technical field of gel breakers for fracturing fluids, and particularly discloses an efficient low-temperature gel breaker for a polymer fracturing fluid. The efficient low-temperature gel breaker comprises an agent A and an agent B. The agent A comprises 35-45 parts of a gel breaking main agent, 3-5 parts of a gel breaking main agent stabilizer, 45-65 parts of mineral oil, 1-2 parts of polyamide and 0.3-0.5 part of hydrogenated castor oil, and the gel breaking main agent is peroxide; the agent B comprises the following components in parts by weight: 5-10 parts of a gel breaking activator, 1-2 parts of an activation stabilizer, 15-20 parts of a gel breaking auxiliary agent, 5-10 parts of a gel breaking retarder, 3-5 parts of an emulsifier, 30-40 parts of white oil and 20-30 parts of water. Compared with a conventional gel breaker system, the low-temperature gel breaker has the advantages that the performance of gel breaking liquid is not reduced during construction, gel breaking is rapid and thorough after construction is completed, the low-temperature gel breaker has the dual functions of liquid construction performance protection and efficient gel breaking, and the problem of gel breaking at the low temperature of 0-50 DEG C is solved.

The invention discloses a method for temporarily plugging diversion fracturing by using a salinity response type emulsion. The method comprises the following steps of 1, preparing the salinity response type emulsion; 2, injecting the salinity response type emulsion to plug old cracks or high-permeability layers; 3, aging the salinity response type emulsion and initiating phase inversion to form plugging; and 4, injecting a fracturing fluid for the diversion fracturing to form new cracks. A salinity response type emulsion-based diverting agent has the advantages of simple preparation, high plugging performance and small formation damage, and solves the problems of low plugging strength, complex use process, difficult gel breaking or degradation, low flowback rate and large formation damage of an existing diverting agent; and the diverting agent can effectively plug the original cracks, and then the new cracks have a certain angle with respect to the original cracks are formed after the diversion fracturing, so that more oil gas seepage channels are formed, the oil drainage area is expanded, the crude oil recovery rate and economic benefits are greatly improved, and the diverting agent is convenient to popularize and use.

The invention relates to a fracturing method of a reservoir. The fracturing method comprises the steps that a first agent, a second agent and a third agent are sequentially added into a stratum; the first agent comprises one or a combination of at least two of mud acid, multi-hydrogen acid and organic acid; the second agent is liquid carbon dioxide; the third agent comprises water-based fracturing fluid and a propping agent; by adopting a specific agent treatment mode, treatment of the total wave and the volume of the reservoir is achieved, a fracture network is constructed in a near-wellbore area, and the minimum main stress of the near-wellbore area is eliminated; the water-based fracturing fluid constructs a main fracture with the high flow conductivity in a far-wellbore area, so that the fracture extends to the deep part of the reservoir, the volume of the fracturing wave is further expanded, and a powerful guarantee is provided for continuous high and stable yield of a subsequent oil and gas well; and the liquid carbon dioxide in the middle section plays a role in promoting flowback and supplementing energy.