152results about How to "Good for flowback" patented technology

The invention relates to an oil well cleanup additive which is applicable to residual liquid cleanup after fracture acidizing of an oil well in an oil field. The cleanup additive comprises the following ingredients according to weight percentage: 7.5-13.5% of dodecyldimethylbenzylammonium chloride, 2-3.5% of fatty alcohol-polyoxyethylene ether, 25-34% of polyoxyethylated alkyl alcohol-8, 3.5-5% of fatty alcohol-polyoxyethylene ether, 0.05-0.1% of fluorocarbon surfactant FN-3, and the allowance of water. A preparation method of the oil well cleanup additive comprises the steps as follows: fatty alcohol-polyoxyethylene ether, JFC-4, polyoxyethylated alkyl alcohol-8 and fatty alcohol-polyoxyethylene ether are added into an enamel reactor by proportion; the temperature is raised to 55-60 DEG C; 5% of water is firstly added while stirring; dodecyldimethylbenzylammonium chloride and fluorocarbon surfactant FN-3 are then added in proportion and stirred for 30 minutes; the water is then added and the mixture is cooled to normal temperature. The oil well cleanup additive reduces the adhesive force of residual construction liquid flowing in reservoir bed, thereby accelerating the flowback of residual liquid by 20-30 percentage points.

The invention discloses a foaming cleanup additive for a gas well. The foaming cleanup additive is composed of a surfactant, a foam stabilizing agent, an auxiliary agent and water. The preparation method comprises a step of uniformly mixing the surfactant, the foam stabilizing agent, the auxiliary agent and water so as to obtain the finished foaming cleanup additive. The foaming cleanup additive has excellent foaming performance, can produce abundant and stable foam and has moderate salt resistance; the foaming cleanup additive has surface tension of 21.11 mN/m and good cleanup performance and is beneficial for flowback of an operation fluid; and the foaming cleanup additive makes full use of all the raw materials, combines a foaming agent and a cleanup additive, realizes two purposes, reduces cost and is convenient to use on site.

The invention provides a nanometer microemulsion cleanup additive. The invention provides a concentrate of the nanometer microemulsion cleanup additive. The concentrate comprises 20-45wt% of oil, 15-45wt% of a surfactant, 0.1-35wt% of a cosolvent, 0.1-5wt% of an organic acid, and the balance of water. The invention also provides the nanometer microemulsion cleanup additive prepared by using the concentrate. Amino silicone oil is used as the necessary component of the oil, so the nanometer microemulsion cleanup additive has high fluid flow-back efficiency; the nanometer microemulsion cleanup additive and a fracturing fluid are injected into an oil well to carry out fracturing reconstruction of an oil-gas reservoir, so the fracturing fluid has a good water lock damage clearing performance and promotes the flow-back of the fracturing fluid, thereby the fracturing reconstruction effect of the oil-gas reservoir is improved, and the output of natural gas is increased; and the nanometer microemulsion cleanup additive is simple to prepare, and is convenient to use.

The invention relates to microemulsion for improving core wettability. The microemulsion consists of a Gimini quaternary ammonium salt cationic surfactant, a nonionic surfactant and an aid of lower alkyl alcohol; a mass ratio of the Gimini quaternary ammonium salt cationic surfactant to the nonionic surfactant is 1:(1-60); and the aid accounts for 30 to 50 mass percent of the microemulsion. The microemulsion has a characteristics of oil-water miscibility, can improve the wetting condition of a stratum to a neutral weakly waterwet condition, and obviously reduce the surface tension of working fluid so as to reduce capillary pressure, remove water lock, reduce starting differential pressure and contribute to the flowback of the working fluid, so that the stratum is prevented from being damaged by the working fluid and the effect of stably increasing production of an oil gas well is achieved.

The invention relates to a novel modification system and process of a hot-dry-rock thermal reservoir, characterized by the combination of two stimulation measure processes, thermal stimulation and chemical stimulation. The process is characterized in that a naturally present fracture network is destructed by thermal stimulation to enhance permeability, partial minerals, scale and obstruction in shafts and fractures are dissolved by the chemical stimulation, and flow guiding capacity of the fractures is further improved. The repeating of the process enables a larger range of thermal reservoirs to be modified. By using the process, the problem of the prior art that after thermal stimulation, part of the fractures are closed along with the rise of the temperature of a cooling area and the problem that that a chemical stimulant disappears nearby an injection location during its excess speed of reacting with rock minerals at high temperature are solved, and the process enables greatly reduction in the risk of frequent microseism in a reservoir modification process when compared to traditional hydrofracturing. The process is widely applicable to the modification of hot-dry-rock thermal reservoirs.

The invention discloses high temperature-resisting cleaning CO2 foam fracturing liquid suitable for unconventional oil and gas reservoir development. The high temperature-resisting cleaning CO2 foam fracturing liquid in gas phase is CO2; the high temperature-resisting cleaning CO2 foam fracturing liquid in liquid phase is high temperature-resisting cleaning fracturing liquid; the foam mass is 52 percent to 75 percent. The high temperature-resisting cleaning CO2 foam fracturing liquid is prepared from the following raw materials in percentage by weight: 0.3 to 0.65 percent of thickening agent, 0.2 to 0.5 percent of viscosity synergist, 0.2 to 0.3 percent of pH (Potential of Hydrogen) value modifier, 0 to 0.2 percent of high-temperature stabilizing agent, 0.01 to 0.1 percent of gel breaker and water, wherein the thickening agent is prepared from acrylamide, vinylpyrrolidone, maleic acid, anionic functional monomers, an initiating agent, inorganic salt and the like; the viscosity synergist is mainly prepared from an anionic surfactant; the pH value modifier is mainly prepared from an organic acid. According to the high temperature-resisting cleaning CO2 foam fracturing liquid disclosed by the invention, the temperature-resisting ability is up to 140 DEG C, the sand carrying performance is excellent, the frictional resistance is low, the foam stability is strong, the content of residual slag is extremely low, the stratum compatibility is good, back flowing is easy, the construction effect is quickly obtained, and important significances to effective development of an unconventional oil and gas reservoir and protection of a reservoir stratum are obtained.

The invention discloses a fracturing prepad fluid, comprising the following ingredients: 1-10 wt% of biological enzyme, 0.1-1 wt% of clay stabilizing agent, 0.01-0.1 wt% of fluorocarbon surfactant, 0.01-0.5 wt% of wettability reversal agent, 0.01-1 wt% of composite activator, and the balance of water. The fracturing prepad fluid disclosed herein not only overcomes the disadvantages of routine prepad fluids and has the advantage of fracture forming of routine prepad fluids, but also has the effects of peeling off residual oil on the surface of a rock core, cleaning and unblocking oil gas seepage channels, reducing the viscosity of crude oil, changing the wetability of the rock core, reducing the surface and interfacial tension to benefit for flowback, and preventing the clay from expansionand migration, and the like. The more the fracturing prepad fluid enters a reservoir, the larger the spread range is, and the larger the action scopes of the fracturing prepad fluid on cleaning and unblocking of the oil gas seepage channels are. The fracturing prepad fluid is beneficial for increasing the oil gas yield.

The invention provides a gel composition and a nitrogen-foamed gel composite temporary plugging agent containing the same. The gel composition comprises the following components in percentage by mass: 1.0% of partially hydrolyzed polyacrylamide, 1.5% of formaldehyde, 0.5% of hydroquinone and the balance of water. The nitrogen-foamed gel composite temporary plugging agent comprises nitrogen and foamed gel, wherein the foamed gel is a mixture of the gel composition and a high-temperature-resistant foaming agent; and the volume ratio of the nitrogen to the foamed gel is (40-60):1. The invention also provides a coupled internal/external swirl foam generator which can be used as a facility for preparing the nitrogen-foamed gel composite temporary plugging agent. The invention also provides a method for inhibiting high-throughput-frequency well steam channeling interference of thick oil, which has the characteristics of small formation damage, strong selectivity for measures and the like and has the effect of gas energization.

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 present invention discloses a retardance and low damage acid solution system for high temperature condensate oil gas reservoir acidification. The acid solution system is suitable for acidification modification of high temperature deep well, particularly condensate gas reservoir, and comprises the following components, by weight, 0.5-3 parts of hydrofluoric acid or 6-12 parts of fluoroboric acid, 8-10 parts of an organic ester, 0.01-0.05 part of a catalyst, 0.1-1 part of a corrosion inhibitor, 0.1-1 part of an iron ion stabilizer, 0.1-1 part of a clay stabilizer, 1-2 parts of a cleanup additive, and 80-100 parts of water. According to the present invention, effects of retardance and corrosion inhibition of the acid solution system can be well achieved at a high temperature, and water blocking can be released and acid solution backflow can be easily achieved with the finally produced methanol and the carbon dioxide.

The invention relates to a high-strength temporary blocking agent for oil and gas wells and a preparation method and application thereof. The temporary blocking agent for oil and gas wells is prepared from the following ingredients through crosslinking reaction: thickening agent, dispersing agent, adhesive and a temperature resistant material with mass ratio of (2.5-3):(1.3-2):(2.8-3):(1.7-2), preferentially, 3:2:3:2. The temporary blocking agent for oil and gas wells has the advantages of high strength, filter cake formation, good solubility and controllable time, flowback is facilitated and the method is simple to operate.

The invention discloses a gas self-production agent, a use of the gas self-production agent, and a self-produced gas foam acidizing method for oil wells and water wells. The gas self-production agent can produce gas in an acid environment or at an oil well bottom temperature. An active ingredient of the gas self-production agent is ammonium carbamate. The gas self-production agent has the advantages of low requirement on gas production conditions, large gas yield, simplification of foam acidizing processes for oil wells and water wells, reduction of a foam acidizing cost, and improvement of acidizing effects.

The invention relates to a temporary plugging steering acidification method applicable to a sandstone reservoir, which belongs to the technical field of yield increasing and injection increasing of oil and gas fields. By adopting pad-acid and synergistic liquid, the temporary plugging of a high permeable layer of the non-homogenous sandstone reservoir can be realized, and the temporary plugging performance is good, so that the subsequently injected main body acid liquid can be successfully diverted to enter a low permeable layer and to acidify the low permeable layer. By adopting the acidification method, the sandstone reservoir can be effectively and homogenously acidified, and the non-homogeneity of the reservoir can be improved.

A variable-viscosity acid liquid is composed of the following compositions in percent by weight: 19.9-25.0% of hydrochloric acid, 1.0-7.5% of hydrofluoric acid, 5-7% of a viscosity-changing agent, 1-2% of an acidifying corrosion inhibitor, 0.1-0.5% of an ferric-ion stabilizing agent, 0.3-0.4% of a demulsification cleanup additive, 1-1.5% of a clay stabilizing agent, 1-2% of an acidifying mutual solvent, and the balance water. The invention provides the variable-viscosity acid liquid, and the variable-viscosity acid liquid has self-diverting flow-dividing effect and is capable of realizing general acidifying and uniform acid distribution.

The invention discloses a clean steering acid liquid system for acidification and a preparation method thereof. The clean steering acid liquid system comprises a solution A and a solution B, wherein the solution A comprises the following raw materials in parts by weight: 32-71 parts of 31% hydrochloric acid solution, 0.5-2.0 parts of ferric ion stabilizer, 0.5-2.0 parts of corrosion inhibitor, 1.0-2.0 parts of surfactant, 3.0-4.0 parts of clay stabilizer, and 19-63 parts of water; the solution B comprises the following raw materials in parts by weight: 8-15 parts of mutual solvent and 85-92 parts of water. The preparation method comprises the following steps: adding the surfactant to a container containing water; evenly agitating, and then adding the clay stabilizer, the corrosion inhibitor and the ferric ion stabilizer; finally adding the hydrochloric acid solution, so as to prepare the solution A; and adding the mutual solvent to the container containing water, so as to prepare the solution B for gel breaking of the clean steering acid liquid system. By adopting the acid liquid system disclosed by the invention, the formula is simple in component, good in steering effect, and free of damage to a reservoir, and controls the self-steering function.

Belonging to the technical field of oilfield chemistry, the invention relates to a modified acrylamide polymer fracturing fluid. The modified acrylamide polymer fracturing fluid is composed of the following components by mass: 0.4-0.6% of a modified acrylamide polymer thickening agent; 0.2-0.5% of a cross-linking agent; 0.1-0.5% of a surfactant; 0.3-1.0% of a clay stabilizer; and the balance water. According to the invention, on the basis of existing fracturing fluid, a vinyl monomer able to inhibit amide group hydrolysis and a salt tolerant and hydrophilic sulfonate group are introduced to the polymer thickening agent, thus greatly enhancing the heat resistance and salt tolerance of the fracturing fluid. A preferable matching crosslinking agent series is selected to reduce the sensitivity of the pH value to crosslinking, and the formed polymer fracturing fluid system has good hot shearing performance and salt resistance. The pH value range of fracturing fluid crosslinking can be widened, and the crosslinking time is moderate. The modified acrylamide polymer fracturing fluid can be widely applicable to fracturing transformation measures of hypotonic reservoirs.

Provided is a slickwater fracturing fluid suitable for being used at a hypersalinity condition. The slickwater fracturing fluid is prepared from, by mass, 0.15-0.45% of polymer viscosifier, 0.05%-0.15% of chelating agent, 0.05%-0.15% of dispersing agent, 0.02%-0.05% of clay stabilizer, 0.30%-0.50% of structure stabilizer, 0.02%-0.06% of gel breaker and the balance water. The slickwater fracturingfluid has the advantages of being low in viscosity, friction and cost and easy to recycle, easily flowing back and the like; the problems are mainly solved that at the hypersalinity condition, polymers are poor in salt resistance and sand-carrying stability and does not easily disperse; the problem can also be solved that vegetable glue fracturing fluid easily rots; after being filtered, flow-backliquid can be further directly recycled, and requirements of large-scale fracturing construction of compact oil-gas reservoirs can be effectively met.

The invention relates to a medium-high temperature oil reservoir phenolic gel self-degradation temporary plugging agent and a preparation method thereof. The temporary plugging agent is prepared fromthe following components in percentage by mass: 2 to 2.5 percent of low molecular weight polymer, 0.2 to 0.25 percent of phenolic cross-linking agent, 0.2 to 0.6 percent of aldehyde cross-linking agent, 0.05 percent of stabilizer, 0.1 percent of catalyst, 0.5 to 2 percent of gel breaker and the balance of water, wherein the sum of the mass percent of all the components is 100 percent. The gel temporary plugging agent provided by the invention can meet the requirements that the oil reservoir temperature is 60-100 DEG C, the plugging time is adjustable within 120-168h, and the gel breaking timeis adjustable within 168-240h; the plugging rate of a rock core reaches 98% or above, the permeability damage rate after gel breaking is 10% or below, a high-permeability layer of a target stratum canbe effectively plugged, flowback is easy after automatic gel breaking, damage to the stratum is extremely small, and the plugging agent can be suitable for most conventional oil reservoirs and has good field application value.

The invention relates to the technical field of fracturing and production increasing of an oil well or natural gas well, and in particular relates to a low damage carboxymethyl hydroxypropyl guanidine gum foam fracturing fluid of a low permeability gas reservoir and a preparation method of the low damage carboxymethyl hydroxypropyl guanidine gum foam fracturing fluid. The low damage carboxymethyl hydroxypropyl guanidine gum foam fracturing fluid of the low permeability gas reservoir contains the following components in parts by weight: 100 parts of base solution, 0.2-0.5 part of cross-linking agent, 0.03-0.04 part of gel breaker, and liquid nitrogen, wherein the liquid nitrogen accounts for 5-7 percent of total volume of the base solution and the cross-linking agent. The base solution, the cross-linking agent and a gel breaker are pumped into an underground fracturing stratum, and the liquid nitrogen is pumped, the base solution, the cross-linking agent, the gel breaker and the liquid nitrogen are mixed uniformly on the underground fracturing stratum, thus the low damage carboxymethyl hydroxypropyl guanidine gum foam fracturing fluid reaches the purpose of fracturing operation, and has the advantages of low content of residue after fracturing, good gel breaking property, rapid flowback, little damage to reservoir stratum water, and good fracturing effect. According to the low damage carboxymethyl hydroxypropyl guanidine gum foam fracturing fluid, the production cost is lowered, and the working efficiency is increased.

The invention discloses a method for improving the permeability of a broken and soft oil and gas reservoir and belongs to the field of oil and gas field development. The method comprises the following steps that a vertical well is vertically-downwards dug from the ground to the position of 1-2 meters below the oil and gas reservoir, and a horizontal well is dug in the horizontal direction. Oriented perforating is conducted from an oil and gas reservoir base plate to the overlying oil and gas reservoir through an oriented perforating gun of the horizontal well, and afterwards fracturing fluid is pumped by a high pressure pump for fracturing the oil and gas reservoir. After fracturing, a seepage passage is formed under the supporting effect of a supporting agent on fracturing fractures, and thus the permeability of the oil and gas reservoir is improved. According to the method for improving the permeability of the broken and soft oil and gas reservoir, on the one hand, fracturing of the oil and gas reservoir and expanding of cracks are facilitated, the permeability of the reservoir is improved; and on the other hand, through the fracturing technology of perforating upwards, fractured rock debris is prone to being discharged from fracturing holes under the gravity effect of the rock debris, and thus the problem that direct fracturing and slag returning are difficult in a coal layer is solved. Meanwhile, through the fracturing technology of perforating upwards, the stress from a bottom rock layer to the upper portion oil and gas reservoir is in a progressively- decreasing state, and thus fracturing of the upper portion oil and gas reservoir is facilitated.