China University of Petroleum

Cankun Lin

Guangqing Zhang

Yuanyuan Wang

Xuelin Zheng

Yongwang Jiang

Yuanxun Nie

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.

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Beijing, China

Cankun Lin