An optimization design method for overall volume fracturing of coalbed methane reservoirs

Abstract

The invention discloses a coalbed methane overall volume fracturing optimization design method which comprises the following steps: with the combination of a coalbed methane development well pattern, implementing capacity simulation on a coalbed methane well group unit, establishing function relationship of volume crack parameters and fracturing construction parameters on the basis of three-dimensional distribution characteristics of coal seam fracturing volume cracks, and finally optimizing the volume crack parameters (volume V of a volume crack and average permeability K) and fracturing construction parameters (support dosage Vf, fracturing liquid amount VL and discharge capacity Q) by taking the maximum net present value of the well group unit within 3 years as a target. The coalbed methane overall volume fracturing optimization design method aims to the optimal matching relationship of volume cracks and reservoir stratums of a fracturing well in the well pattern, so that the optimization result is relatively high in reliability, and meanwhile by adopting a mode that technical parameters are combined with economic optimization, the optimization result is relatively high in economical efficiency and practicability, and effective guidance can be provided for optimization design of coalbed methane fracturing parameters.

Description

technical field [0001] The invention relates to an optimal design method for integral volume fracturing in the development of coal bed gas reservoirs in the petroleum field. Background technique [0002] Coal bed methane belongs to unconventional natural gas and is an important high-quality clean energy. According to the results of the new round of national oil and gas resource assessment, my country's coalbed methane resources are very rich, and the geological resources of coalbed methane buried below 2000m reach 36.81×10 12 m 3 , the technically recoverable resources are 20.48×10 12 m 3 . Although my country has initially realized the ground industrial production of coalbed methane, the total output is still not ideal, and relevant technical research and research are urgently needed. [0003] Since most of the coalbed methane (methane) in the coal seam is stored on the surface of coal seam pores in an adsorbed state, the adsorbed methane must be desorbed from the coal...

AI Technical Summary

Problems solved by technology

At present, the fracturing optimization design of coalbed methane mainly adopts the overall fracturing design method based on the shape of double-wing fractures in traditional sandstone formations, which cannot meet the complex volumetric fracture characterization of coalbed methane reservoirs.

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