A moderately sand-increased pressurized acid fracturing method to improve the stimulation effect of fractured-vuggy reservoirs

Abstract

The present invention relates to a method for moderately adding sand and pressurizing acid fracturing to improve the reconstruction effect of fracture-cavity reservoirs. width, take 1 / 3 of the average fracture width as the upper limit D of the proppant particle size, and measure the safe sand concentration R when the proppant particle size is D; (2) Determine the natural fractures in the target reservoir opened by acid fracturing (3) Carry out acid fracturing construction with sand and pressurization on the target reservoir. The present invention is based on the characteristics of rapid net pressure increase after adding sand in the fracture-cavity reservoir, through dynamic adjustment of the pumping program, real-time optimal scheme, after acid fracturing, the residual acid and proppant are transported to the far end of the fracture together to form a near-end acid-etched support, The remote proppant support can enhance the flow diversion capacity of the seepage channels within the acid pressure sweep range, and improve the production efficiency of fracture-vuggy oil and gas reservoirs, which has broad market application prospects.

Description

technical field [0001] The invention belongs to the field of oil and gas field development, and in particular relates to an acid fracturing process for moderately adding sand and pressurizing to improve the reconstruction effect of fracture-cavity reservoirs. Background technique [0002] Acid fracturing is one of the most important production stimulation measures for the efficient development of carbonate reservoirs. According to the difference in storage and seepage space, formulating an appropriate production stimulation process is conducive to improving the extraction efficiency and recovery level of resources. The matrix permeability of fractured-vuggy reservoirs is extremely low, and generally does not contain oil and gas, while the dissolution pores are mostly distributed along the weak surface structure. Some methods are used to induce acid fluid to leak out along natural fractures, open and drive natural fractures to expand, thereby increasing acid erosion. The numb...

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Problems solved by technology

Although these acid fracturing processes take into account the construction of the conductivity of acid-etched fractures, the optimization of the distal extension of fractures, and the timeliness of the conductivity of the fracture system, they are difficult to achieve when opening the weak surface structure of dissolved pores and driving natural fractures through acid fluid loss. The effect of expansion and other aspects is limited, which limits the development effect of acid fracturing technology on fractured-vuggy oil and gas reservoirs

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