Abstract: The invention introduces a method of calculating etching profile of acid-etched fracture system considering complex filtration media, which mainly considers dynamic filtration caused by natural fractures and acid-etched wormholes in acid fracturing, calculates the above filtration process by a numerical method, and finally calculates acid etching profile of acid-etched fracture system based on acid concentration profile. Calculation equations include fluid pressure in natural fractures, filtration velocity in natural fractures, fracture geometry of hydraulic fractures, fluid pressure in matrix rock, acid concentration profile in natural fractures and hydraulic fractures, acid etching width in hydraulic fractures and natural fractures, and length of acid-etched wormhole, etc.

Abstract: An experimental test method for dynamic imbibition capacity of shale is provided. The method includes the following steps: core preparation; physical parameter test of shale; experimental loading conditions are determined according to formation stress, formation temperature and hydraulic fracturing parameters; and a dynamic imbibition saturation is defined to characterize a dynamic imbibition amount. Various factors, such as fracturing fluid flow, formation confining pressure, formation temperature and fluid pressure, are used to obtain change rules of dynamic imbibition with time under different construction parameters in shale fracturing process.

Abstract: The invention discloses a plate holder for simulating flowing of multiphase fluids in fractures, comprising a rectangular box, provided with a fluid inlet and a fluid outlet at the left and right sides respectively, the fluid inlet is connected to a piston at the fluid inlet, the fluid outlet is connected to a piston at the fluid outlet, an internal flow channel of the piston is arranged as a flared guide groove, and the cavity between the pistons is a rock plate cavity; a pair of horizontally-overlapped rectangular rock plates are installed in the rock plate cavity, four sides parallel to the length direction of the rock plate are completely attached and covered with rubber, the outer side of the rubber is covered with steel plate, fastening screws are installed vertically on the four sides of the box that are directly opposite to the steel plate.

Abstract: A method for determining a favorable time window of an infill well of an unconventional oil and gas reservoir, which comprises the following steps: S1, establishing a three-dimensional geological model with physical properties and geomechanical parameters; S2, establishing a natural fracture network model in combination with indoor core-logging-seismic monitoring; S3, calculating complex fractures in hydraulic fracturing of parent wells; S4, establishing an unconventional oil and gas reservoir model and calculating a current pore pressure field; S5, establishing a dynamic geomechanical model and calculating a dynamic geostress field; S6, calculating complex fractures in horizontal fractures of the infill well in different production times of the parent wells based on pre-stage complex fractures and the current geostress field; S7, analyzing a microseismic event barrier region and its dynamic changes in infill well fracturing; and S8, analyzing the productivity in different infill times, and determining an inf

Abstract: The invention introduces a method of calculating etching profile of acid-etched fracture system considering complex filtration media, which mainly considers dynamic filtration caused by natural fractures and acid-etched wormholes in acid fracturing, calculates the above filtration process by a numerical method, and finally calculates acid etching profile of acid-etched fracture system based on acid concentration profile. Calculation equations include fluid pressure in natural fractures, filtration velocity in natural fractures, fracture geometry of hydraulic fractures, fluid pressure in matrix rock, acid concentration profile in natural fractures and hydraulic fractures, acid etching width in hydraulic fractures and natural fractures, and length of acid-etched wormhole, etc.

Abstract: The present invention discloses a method for experimentally determining the conductivity distribution of an acid-fractured fracture a carbonate rock oil and gas reservoir, including the following steps: by an acid fracturing simulator FracproPT, simulating and acquiring distribution data of fracture width, fracture height, temperature and acid liquor mass concentration in a hydraulic fracture length direction; selecting fracture width, fracture height and temperature data of total 10 feature points with the acid liquor mass concentrations being from 100% to 10% of the initial mass concentration; converting site acid injection displacement into laboratory acid injection displacement; preparing experimental acid liquor according to the acid liquor mass concentration data of the 10 feature points; and simulating the acid etching process, and experimentally testing the conductivity under the condition of reservoir closed pressure, and drawing a distribution diagram of the acid-etched fracture conductivity in the

Abstract: A method for determining a favorable time window of an infill well of an unconventional oil and gas reservoir, which comprises the following steps: S1, establishing a three-dimensional geological model with physical properties and geomechanical parameters; S2, establishing a natural fracture network model in combination with indoor core-logging-seismic monitoring; S3, calculating complex fractures in hydraulic fracturing of parent wells; S4, establishing an unconventional oil and gas reservoir model and calculating a current pore pressure field; S5, establishing a dynamic geomechanical model and calculating a dynamic geostress field; S6, calculating complex fractures in horizontal fractures of the infill well in different production times of the parent wells based on pre-stage complex fractures and the current geostress field; S7, analyzing a microseismic event barrier region and its dynamic changes in infill well fracturing; and S8, analyzing the productivity in different infill times, and determining an inf

Abstract: A method for acquiring an opening timing of natural fracture under an in-slit temporary plugging condition and a device thereof are provided. The method includes steps of: acquiring physical parameters of stratum according to site geological data, and measuring a slit length L of a hydraulic fracture; dividing the hydraulic fracture into N unit bodies of equal length and numbering them sequentially; and dividing a total calculation time t into meter fractions of time with equal interval; calculating a width of each unit body in the hydraulic fracture at the initial time; calculating a fluid pressure in the hydraulic fracture at the k-th fraction of time; calculating a closed pressure at an entrance of the natural fracture on an upper side and a lower side of the hydraulic fracture at the k-th fraction of time; and determining whether the natural fracture is opened by a determining criteria based on the above calculation results.

Abstract: A method for acquiring an opening timing of natural fracture under an in-slit temporary plugging condition and a device thereof are provided. The method includes steps of: acquiring physical parameters of stratum according to site geological data, and measuring a slit length L of a hydraulic fracture; dividing the hydraulic fracture into N unit bodies of equal length and numbering them sequentially; and dividing a total calculation time t into in time nodes with equal interval; calculating a width of each unit body in the hydraulic fracture at the initial time; calculating a fluid pressure in the hydraulic fracture at the k-th time node; calculating a closed pressure at an entrance of the natural fracture on an upper side and a lower side of the hydraulic fracture at the k-th time node; and determining whether the natural fracture is opened by a determining criteria based on the above calculation results.

Abstract: An experimental testing device and method for dynamic imbibition capacity of shale are provided.

Abstract: The invention discloses a method for evaluating the longitudinal deformation of proppant pack, mainly comprising the following steps: displace the proppant evenly on one steel sheet and cover the proppant with another same steel sheet; place pistons on the outer surface of two steel sheets respectively to form a test unit; place the test unit on fracture conductivity tester, compact the proppant pack at a pressure of 0.6 MPa, measure the width between the two steel sheets at the four corners of the steel sheet, and calculate the average results; install the left and right displacement meters, increase the closure pressure from 6.9 MPa to 69 MPa with an increment of 6.

Abstract: The invention discloses a plate holder for simulating flowing of multiphase fluids in fractures, comprising a rectangular box, provided with a fluid inlet and a fluid outlet at the left and right sides respectively, the fluid inlet is connected to a piston at the fluid inlet, the fluid outlet is connected to a piston at the fluid outlet, an internal flow channel of the piston is arranged as a flared guide groove, and the cavity between the pistons is a rock plate cavity; a pair of horizontally-overlapped rectangular rock plates are installed in the rock plate cavity, four sides parallel to the length direction of the rock plate are completely attached and covered with rubber, the outer side of the rubber is covered with steel plate, fastening screws are installed vertically on the four sides of the box that are directly opposite to the steel plate.

Abstract: The invention discloses a testing device and method for evaluating effects of CO2 reaction rate of acid rock plate. The testing device includes an acid fluid conveying unit, a CO2 conveying unit, a mixing tank, a plate holder, a recycling fluid tank, and a vacuum pump. The mixing tank includes an acid fluid inlet, a CO2 inlet, and a miscible fluid outlet. The acid fluid inlet is connected with the acid fluid conveying unit, the CO2 inlet is connected with the CO2 conveying unit, the miscible fluid outlet is connected with the plate holder, the plate holder is connected with the recycling fluid tank, and the recycling fluid tank is connected to the vacuum pump. The CO2 conveying unit includes a CO2 cylinder and a gas booster pump which is connected to the cylinder. The outlet of the pump is connected to the gas inlet of the mixing tank.

Abstract: A method for characterizing complexity of rock fracture based on fractal dimension and a device thereof are provided. The method includes steps of: collecting rock fracture samples of a rock, and collecting basic parameters of the rock; determining a fractal dimension of a rock fracture morphology of the rock; calculating the fractal dimension of the rock; calculating a complexity coefficient Fc of rock fracture of the rock; and characterizing a complexity of rock fracture of the rock based on the complexity coefficient Fc of rock fracture of the rock. In the present invention, combined with the fractal geometry theory, fracture complexity coefficient of shale rocks is redefined and calculated to accurately characterize rock fracture morphology, so that characteristics of rock fracture morphology is correctly understood and affecting factors of fracture morphology is analyzed.

Abstract: Techniques in horizontal well completions that facilitate multistage fracturing may be performed in shale gas reservoirs. The techniques may involve the creation of large scale fracture networks, connecting the reservoir and the wellbore, facilitated by activating pre-existing natural fractures (NFs). In addition, geo-mechanical characteristics facilitate the optimization of maximum stimulated reservoir volumes (SRVs). In particular, completion optimization patterns are provided for horizontal wellbores, designated herein as altered alternate fracturing (AAF) completions. Completion optimization patterns may involve a multi-step combination of simultaneous and alternate fracturing patterns. Additionally, the dynamic evolution and progression of NF growth are modeled using a variety of alternative criteria. Further, specific analyses are provided of how the well completion pattern influences the fracture network.

Abstract: The present invention discloses a method for experimentally determining the influence of acid liquor on the Young modulus of compact carbonate rock.

Abstract: The invention provides techniques that relate to horizontal well completions that facilitate multistage fracturing, for example, in shale gas reservoirs. Aspects of these techniques involve the creation of large scale fracture networks, connecting the reservoir and the wellbore, facilitated by activating pre-existing natural fractures (NFs). Taking into account selected shale formation geo-mechanical characteristics facilitates the optimization of maximum stimulated reservoir volumes (SRVs). In particular, completion optimization patterns are provided for horizontal wellbores, designated herein as altered alternate fracturing (AAF) completions. Aspects of this approach involve a multi-step combination of simultaneous and alternate fracturing patterns. To illustrate aspects of optimization, the dynamic evolution and progression of NF growth are modeled using a variety of alternative criteria. In addition, specific analyses are provided of how the well completion pattern influences the fracture network.

Abstract: The present invention discloses a method for experimentally determining the conductivity distribution of an acid-fractured fracture a carbonate rock oil and gas reservoir, including the following steps: by an acid fracturing simulator FracproPT, simulating and acquiring distribution data of fracture width, fracture height, temperature and acid liquor mass concentration in a hydraulic fracture length direction; selecting fracture width, fracture height and temperature data of total 10 feature points with the acid liquor mass concentrations being from 100% to 10% of the initial mass concentration; converting site acid injection displacement into laboratory acid injection displacement; preparing experimental acid liquor according to the acid liquor mass concentration data of the 10 feature points; and simulating the acid etching process, and experimentally testing the conductivity under the condition of reservoir closed pressure, and drawing a distribution diagram of the acid-etched fracture conductivity in the