China University of Petroleum

Guangqing Zhang

Yuanyuan Wang

Cankun Lin

Xuelin Zheng

Xiao Yang

Ying Lin

Yongwang Jiang

Xuejing Han

Yuanxun Nie

The present invention discloses an apparatus and a method for evaluating properties of a temporary plugging agent based on acoustic emission, wherein the apparatus includes a fracturing machine, an acoustic emission sensor and an acoustic emission analyzer, wherein the fracturing machine is configured to load a sample when oil pressure is stable and remains unchanged in a fracture of the sample, a real fracturing condition being simulated for the sample, and oil being pumped in and a temporary plugging agent being placed into the fracture; the acoustic emission sensor is configured to detect an acoustic wave signal emitted by the sample when the fracturing machine loads the sample; and the acoustic emission analyzer is connected to the acoustic emission sensor and configured to determine that the temporary plugging agent is fractured when a fracture signal occurs in the acoustic wave signal. The present invention can obtain the fracture information of the sample without disturbing the normal experimental process and experimental results, and the experimental measurement results are more practical.

Apparatus and method for evaluating properties of temporary plugging agent based on acoustic emission

The present application provides a horizontal well multi-section multi-stage reciprocating fracturing method and apparatus. The method comprises the steps of: dividing a fracturing tubular column into n fracturing sections; fracturing the first fracturing section to form a first first-stage fracture; fracturing the second fracturing section to form a second first-stage fracture; fracturing the first fracturing section again to form a first second-stage fracture; going on in this way, fracturing the nth fracturing section to form an nth first-stage fracture; fracturing the (n&#x2212;1)th fracturing section again to form an (n&#x2212;1)th second-stage fracture; going on in this way, at last, fracturing the nth fracturing section again to form an (n)th-stage fracture. The present method and apparatus can effectively eliminate or reduce the interference of relatively long fractures that has been generated during the horizontal well multi-section fracturing to fractures generated by subsequent fracturing.

Horizontal well multi-section multi-stage reciprocating fracturing method and apparatus

A fracturing method for creating a complex crack network by intermittent fracturing on site, which relates to oil and gas field development, and comprises the following steps: pumping a fracturing fluid into an oil well to enter the reservoir, continuing pumping the fracturing fluid into fractured cracks after a pumping pressure has reached a preset pressure, and stopping pumping the fracturing fluid after a preset condition has been reached; performing under-pressure shut-in for the oil well; stopping the shut-in operation when a signal detecting vehicle cannot receive an obvious microseismic signal in the under-pressure shut-in process; repeating the above three steps multiple times; pumping the fracturing fluid into the oil well to enter the reservoir by the fracturing truck until an amount of the pumped in fracturing fluid reaches a design pump-in liquid amount; pumping a sand-carrying fluid into the oil well to enter the reservoir by means of a sand blending truck and the fracturing truck after the amount of the pumped in fracturing fluid has reached the design pump-in liquid amount, and stopping pumping the sand-carrying fluid after the pumped in sand-carrying fluid has reached a preset sand adding amount.

Fracturing method for creating complex crack network by intermittent fracturing on site

The present invention provides a supercritical carbon dioxide core fracturing holder under pore pressure saturation, including a holding sleeve; a left end sleeve and a right end sleeve are correspondingly embedded at the two end ports of the holding sleeve, and a fixed plug is docked to the left end sleeve; a moving plug movably passes through the right end sleeve, and a piston ring is formed on the outer side face of the moving plug; a sealing rubber sleeve for holding a test sample is disposed; two axial fluid injection pipelines are correspondingly disposed within the fixed plug and the moving plug; and an axial displacement measuring device is disposed between the outer end of the right end sleeve and the moving plug, and a fluid injection chamber is formed between the inner wall of the holding sleeve and the outer side face of the sealing rubber sleeve.

Supercritical carbon dioxide fracturing core holder under the influence of pore pressure saturation

The present invention relates to a visualized supercritical carbon dioxide fracturing physical simulation test method, comprising: preparing a rock sample, preparing a prefabricated fracture; curing the rock sample; fixing the cured rock sample in a confining pressure chamber, and applying a preset three-way confining pressure and pore pressure to the rock sample; turning on a high-speed camera, injecting supercritical carbon dioxide fracturing fluid to the central hole, and continuously recording a fluid injection pressure and test surface image information of the rock sample until the test is ended; observing a hydraulic fracture inside. Through this method, it is possible to obtain images in the whole process of initiation and extension of the artificial fracture during supercritical carbon dioxide fracturing, and distribution rules of parameters, such as stress, strain and pore pressure on the surfaces of the rock sample.

Visualized supercritical carbon dioxide fracturing physical simulation test method

An experimental method for indoor real-time dynamic monitoring of a hydraulic fracture width, comprising the steps of: test piece preparation: assembling a prefabricating mold and fixing a fiber grating therein; mounting a simulated wellbore in the prefabricating mold, pouring agitated cement mortar into the prefabricating mold, and the cement mortar is solidified to form a test piece; mounting the test piece into a confining pressure chamber of a true triaxial hydraulic fracturing simulation device, connecting a liquid injection line to the true triaxial hydraulic fracturing simulation device, and connecting the fiber grating to a modem that is connected to a computer; hydraulic fracture width monitoring test: injecting liquid into the confining pressure chamber of the true triaxial hydraulic fracturing simulation device through the liquid injection line to apply three-direction confining pressures to the test piece, injecting liquid into the simulated wellbore, and starting the fiber grating and the modem to dynamically monitor the hydraulic fracture width in the test piece; and when a hydraulic fracture inside the test piece reaches an outer surface of the test piece, ending the test.

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Beijing, China

Guangqing Zhang