Abstract: Disclosed is a system for segmented simultaneous water injection and oil recovery through double pipes in horizontal section, comprising several packers, several oil-extracting mechanisms and several water-injection mechanisms, wherein each of the packers, each of the oil-extracting mechanisms, and each of the water-injection mechanisms has an injection channel and a production channel, when several packers, several oil-extracting mechanisms and several water-injection mechanisms are combined, each of the injection channels is connected in turn, and each of the production channels is also connected in turn, the oil-extracting mechanism can extract oil through the production channel, the water-injection mechanism can inject water through the injection channel. The beneficial effects of this disclosure include: the oil in the oil production section can be produced while the water injection section is injected with water.

Abstract: Disclosed is a fracturing method with synergistic effects of energy enhancement, oil displacement, huff and puff, imbibition, and displacement, comprising the following steps: selecting a well that has never been fracted as a fracturing well; dividing the target layer into several fracturing intervals; performing perforating operations on each fracturing interval of the fracturing well; injecting pore cleaning fluid into the fracturing well to perform pore cleaning and acidizing pretreatment on each cluster perforation; designing fracturing construction parameters; alternately injecting slick water fracturing fluid and oil-displacement slick water fracturing fluid into each of the fracturing layers. The beneficial effects of this disclosure are: the construction method of slick water fracturing fluid with high pump rate and large displacement can form a more complex fracture network structure, tap the production potential of the target reservoir, and further improve the stimulation effect of the reservoir.

Abstract: Disclosed is a system for segmented simultaneous water injection and oil recovery through double pipes in horizontal section, comprising several packers, several oil-extracting mechanisms and several water-injection mechanisms, wherein each of the packers, each of the oil-extracting mechanisms, and each of the water-injection mechanisms has an injection channel and a production channel, when several packers, several oil-extracting mechanisms and several water-injection mechanisms are combined, each of the injection channels is connected in turn, and each of the production channels is also connected in turn, the oil-extracting mechanism can extract oil through the production channel, the water-injection mechanism can inject water through the injection channel. The beneficial effects of this disclosure include: the oil in the oil production section can be produced while the water injection section is injected with water.

Abstract: Disclosed is a device for evaluating damage of fracturing fluid to reservoir and operation method thereof, the device includes a liquid storage tank, a suction tube, a chromatography device, a bracket, a receiving container and a height adjuster; the disclosure has the following beneficial effects: since different liquids pass through the porous medium at different time and speed and the silica gel particles will not expand when immersed in the liquid, a porous structure is formed by placing silica gel particles of different sizes to simulate the pore-throat structure of unconventional oil and gas reservoirs, hence removing the influence of fracturing fluid on the hydration and expansion damage of the reservoir matrix, by testing the time and flow rate of different fracturing fluids flowing through the silica gel pores, the degree of damage caused by fracturing fluids to unconventional oil and gas reservoirs is evaluated.

Abstract: Disclosed is a fracturing method with synergistic effects of energy enhancement, oil displacement, huff and puff, imbibition, and displacement, comprising the following steps: selecting a well that has never been fracted as a fracturing well; dividing the target layer into several fracturing intervals; performing perforating operations on each fracturing interval of the fracturing well; injecting pore cleaning fluid into the fracturing well to perform pore cleaning and acidizing pretreatment on each cluster perforation; designing fracturing construction parameters; alternately injecting slick water fracturing fluid and oil-displacement slick water fracturing fluid into each of the fracturing layers. The beneficial effects of this disclosure are: the construction method of slick water fracturing fluid with high pump rate and large displacement can form a more complex fracture network structure, tap the production potential of the target reservoir, and further improve the stimulation effect of the reservoir.

Abstract: Disclosed is a device for evaluating damage of fracturing fluid to reservoir and operation method thereof, the device includes a liquid storage tank, a suction tube, a chromatography device, a bracket, a receiving container and a height adjuster; the disclosure has the following beneficial effects: since different liquids pass through the porous medium at different time and speed and the silica gel particles will not expand when immersed in the liquid, a porous structure is formed by placing silica gel particles of different sizes to simulate the pore-throat structure of unconventional oil and gas reservoirs, hence removing the influence of fracturing fluid on the hydration and expansion damage of the reservoir matrix, by testing the time and flow rate of different fracturing fluids flowing through the silica gel pores, the degree of damage caused by fracturing fluids to unconventional oil and gas reservoirs is evaluated.

Abstract: A main chain of a temperature-resistant and anti-collapse multi-branched polymer fluid loss reducer is composed of the following repeating unit (I): In the repeating unit (I): x:y:z=(20˜80):(20˜80):(2˜30); the R1 and R2 groups are alkylamines having a multi-branched structure. The beneficial effect of the multi-branched polymer fluid loss reducer is: introducing cheap acrylamide branch monomer into the polymer monomer system of acrylamide and 2-acrylamido-2-methylpropanesulfonic acid, the preparation process is simple, the reaction conditions are mild, and the production cost is significantly reduced.

Abstract: The invention discloses a carboxymethyl inulin graft polymer scale and corrosion inhibitor and a preparation method thereof. The main chain of the carboxymethyl inulin graft polymer scale and corrosion inhibitor consists of the following repeating unit (I): in the repeating unit (I), x:y=(20˜80):(20˜80); the range of z is from 2 to 70, the degree of carboxymethyl substitution is from 1.5 to 2.5. The beneficial effect of the technical scheme proposed in the present invention is: it has excellent scale inhibition and corrosion inhibition properties; the monomers are cheap and easily available; the reaction conditions are mild and easy to control; at the same time, the monomer raw materials don't contain phosphorus and nitrogen, and are environmentally friendly.

Abstract: Disclosed is a method for determining three-dimensional in-situ stress based on displacement measurement of borehole wall, including the following steps: pumping the prefluid and the sand-carrying fluid into the target interval, and injecting the biological oil displacement agent into the target interval in sequence; pumping temporary plugging agent into the target layer to implement crack plugging diverting; pumping the sand-carrying liquid into the target interval, and injecting the biological oil displacement agent into the target interval. The beneficial effect of the technical scheme proposed in this disclosure is: by injecting oil displacement agent to fracturing fluid, the temporary plugging diverting fracturing is integrated constructed with enhanced oil recovery, at the same time, it can overcome the incomplete removal of temporary plugging agent and the water lock effect of fracturing fluid caused by diverting fracturing.

Abstract: An enhanced oil recovery method includes: screening out implementation well that meet the requirements of a preset standard; selecting the target interval that can be used for enhanced oil recovery in the implementation well; obtaining the reservoir parameters and perforation parameters of the target interval, so as to divide the target interval into several groups of swallowing and exhaling segments, injecting the infection liquid containing and simmer the well for a period of time; and after the well simmering, the oil-water mixture replaced by the injection fluid is produced from each exhaling segment.

Abstract: Disclosed is a method for determining three-dimensional in-situ stress based on displacement measurement of borehole wall, including the following steps: pumping the prefluid and the sand-carrying fluid into the target interval, and injecting the biological oil displacement agent into the target interval in sequence; pumping temporary plugging agent into the target layer to implement crack plugging diverting; pumping the sand-carrying liquid into the target interval, and injecting the biological oil displacement agent into the target interval. The beneficial effect of the technical scheme proposed in this disclosure is: by injecting oil displacement agent to fracturing fluid, the temporary plugging diverting fracturing is integrated constructed with enhanced oil recovery, at the same time, it can overcome the incomplete removal of temporary plugging agent and the water lock effect of fracturing fluid caused by diverting fracturing.

Abstract: The invention discloses a three-dimensional cage-like hyperbranched monomer and preparation method and application thereof. The three-dimensional cage-like hyperbranched monomer has the structural formula I: wherein in the structural formula I: X is any one of —O, —S, —NH; y is any integer from 2 to 8; R is —H or —CH3. The beneficial effect of the technical scheme proposed in the present invention is: by introducing easily polymerizable olefin groups, the carboxyl group and amide group are combined in the three-dimensional cage-like hyperbranched monomer to make the water solubility good, and it can be copolymerized with many other monomers to obtain the three-dimensional cage-like hyperbranched polymer; when used as an additive for wellbore working fluids, due to the hyperbranched structure of the polymer, it has good salt and temperature resistance, and also has viscosity increasing, filtration loss, and flocculation properties; meanwhile, the synthesis method is simple and the cost is low.

Abstract: Disclosed is slick water volumetric fracturing method with large liquid volume, high flow rate, large preflush and low sand ratio, including the following steps: (a) evaluating the reservoir parameters; (b) determining the perforation position and a perforation parameters of a fracturing interval; (c) determining the fracturing parameters; (d) performing a perforation operation on the fracturing interval; (e) injecting acidizing fluids into the perforation; (f) alternately injecting preflush and sand-laden fluids into the fracturing interval several times; (g) injecting displacement fluids into the fracturing interval; wherein the flow rate is not less than 12 m3/min. The beneficial effect of the technical scheme proposed in the present invention is: by using a low viscosity slick water fracturing fluid with high flow rate, the pressure of the fracturing fluid is increased, thereby increasing the stimulated reservoir volume and increasing the fracturing yield.

Abstract: Disclosed is an integrated construction method of fracturing and tertiary oil recovery for low-permeability reservoir, including the following steps: dividing the target layer into several fracturing intervals; determining the amount of fracturing fluid required for the target fracturing interval; determining the flow rate of the target fracturing interval; determining the pumping construction procedure for the target fracturing interval; perforating the target fracturing interval; injecting oil displacement fracturing fluid into the target fracturing interval for fracturing construction; wherein the oil displacement fracturing fluid is a fracturing fluid to which an oil displacement agent is added.

Abstract: The invention discloses a carboxymethyl inulin graft polymer scale and corrosion inhibitor and a preparation method thereof. The main chain of the carboxymethyl inulin graft polymer scale and corrosion inhibitor consists of the following repeating unit (I): in the repeating unit (I), x:y=(20˜80):(20˜80); the range of z is from 2 to 70, the degree of carboxymethyl substitution is from 1.5 to 2.5. The beneficial effect of the technical scheme proposed in the present invention is: it has excellent scale inhibition and corrosion inhibition properties; the monomers are cheap and easily available; the reaction conditions are mild and easy to control; at the same time, the monomer raw materials don't contain phosphorus and nitrogen, and are environmentally friendly.

Abstract: The invention discloses a three-dimensional cage-like hyperbranched monomer and preparation method and application thereof. The three-dimensional cage-like hyperbranched monomer has the structural formula I: in the formula: X is any one of —O, —S, —NH; y is any integer from 2 to 8; R is —H or —CH3. The beneficial effect of the technical scheme proposed in the present invention is: by introducing easily polymerizable olefin groups, the carboxyl group and amide group are combined in the three-dimensional cage-like hyperbranched monomer to make the water solubility good, and it can be copolymerized with many other monomers to obtain the three-dimensional cage-like hyperbranched polymer; when used as an additive for wellbore working fluids, due to the hyperbranched structure of the polymer, it has good salt and temperature resistance, and also has viscosity increasing, filtration loss, and flocculation properties; meanwhile, the synthesis method is simple and the cost is low.

Abstract: The invention discloses a temperature-resistant and anti-collapse multi-branched polymer fluid loss reducer and preparation method thereof. The main chain of the temperature-resistant and anti-collapse multi-branched polymer fluid loss reducer is composed of the following repeating unit (I): In the repeating unit (I): x:y:z=(20˜80):(20˜80):(2˜30); the R1 and R2 groups are alkylamines having a multi-branched structure. The beneficial effect of the technical scheme proposed in the present invention is: introducing cheap acrylamide branch monomer into the polymer monomer system of acrylamide and 2-acrylamido-2-methylpropanesulfonic acid, the preparation process is simple, the reaction conditions are mild, and the production cost is significantly reduced. At the same time, the polymerized monomer does not contain aromatic ring monomers and ionizable monomers, is environmentally friendly, and maintains excellent temperature resistance, salt resistance and anti-collapse properties.

Abstract: Disclosed is an integrated construction method of fracturing and tertiary oil recovery for low-permeability reservoir, including the following steps: dividing the target layer into several fracturing intervals; determining the amount of fracturing fluid required for the target fracturing interval; determining the flow rate of the target fracturing interval; determining the pumping construction procedure for the target fracturing interval; perforating the target fracturing interval; injecting oil displacement fracturing fluid into the target fracturing interval for fracturing construction; wherein the oil displacement fracturing fluid is a fracturing fluid to which an oil displacement agent is added.

Abstract: Disclosed is slick water volumetric fracturing method with large liquid volume, high flow rate, large preflush and low sand ratio, including the following steps: (a) evaluating the reservoir parameters; (b) determining the perforation position and a perforation parameters of a fracturing interval; (c) determining the fracturing parameters; (d) performing a perforation operation on the fracturing interval; (e) injecting acidizing fluids into the perforation; (f) alternately injecting preflush and sand-laden fluids into the fracturing interval several times; (g) injecting displacement fluids into the fracturing interval; wherein the flow rate is not less than 12 m3/min. The beneficial effect of the technical scheme proposed in the present invention is: by using a low viscosity slick water fracturing fluid with high flow rate, the pressure of the fracturing fluid is increased, thereby increasing the stimulated reservoir volume and increasing the fracturing yield.

Abstract: The present invention relates to a milk-like friction reducer used in slick water fracturing and belongs to the technical field of oilfield chemicals. This friction reducer is obtained via free radical polymerization in water by using component A, component B and component C; wherein said component A is a mix of nonionic water-soluble monomers having carbon-carbon double bond; wherein said component B is a mix of water-soluble polymeric stabilizers obtained from monovalent cationic monomers; and wherein said component C is a mix of monovalent inorganic salts. The present invention is environmentally-friendly and easy to use. Its subsequent friction reducer is convenient to add on-the-fly and leads to no foaming without adding anti-foamer. Moreover, unlike other regular friction reducers, it is tolerant with various brines and compatible with common oilfield additives. The subject friction reducer can achieve an extent of friction reduction of greater than 70%.