Fracturing fluid flowback quantity calculating method of fractured sandstone gas reservoir fracturing horizontal well

Abstract

The invention discloses a fracturing fluid flowback quantity calculating method of a fractured sandstone gas reservoir fracturing horizontal well. The fracturing fluid flowback quantity calculating method comprises the steps: (1) based on on-site fracture data, the fracture distribution fractal dimension Dc, the fracture length fractal dimension D1, the fracture density coefficient alpha, and theFisher constant K of target reservoir blocks are obtained through calculation; (2) a reservoir fractal discrete fracture network model is generated through obtained fracture parameters; (3) the equivalent permeability tensor of the fractal discrete fracture network model is calculated; (4) the equivalent permeability tensor is substituted into a continuity equation of a gas-liquid two-phase seepage flow, and a fracturing fluid flowback model is established; and (5) the fracturing fluid flowback model is solved, the liquid-phase saturation degree is obtained, and thus the flowback quantity of fracturing fluid is calculated. Influences of natural fractures are considered, the calculation result has more authenticity and accuracy, the principle is reliable, operation is easy and convenient, the theoretical basis can be provided for effect evaluation and productivity prediction after fracturing of the fractured sandstone gas reservoir fracturing horizontal well, and the defects of the prior art are overcome.

Description

technical field [0001] The invention belongs to the field of oil and gas field development, and in particular relates to a method for calculating the flowback volume of fracturing fluid for fracturing horizontal wells in fractured sandstone gas reservoirs. Background technique [0002] As the development of most conventional oil and gas fields in my country has come to an end, as the next strategic successor area for oil and gas development, unconventional oil and gas reservoirs have gradually become a new force in the development of the petroleum industry. Among them, tight sandstone gas reservoirs are an important field for unconventional oil and gas development, which is also an inevitable trend of the country's strategic measures for energy conservation, environmental protection and sustainable development. Due to the extremely low permeability of tight sandstone gas reservoirs, economic benefits can only be obtained after hydraulic fracturing. Through staged multi-clus...

AI Technical Summary

Problems solved by technology

At present, domestic and foreign studies on fracturing fluid flowback mainly focus on the seepage mechanism of fracturing fluid in reservoirs, while natural fractures are often ignored or simplified (Peng Cao, Jishan Liu, Yee-Kwong Leong. A multiscale-multiphasesimulation model for the evaluation of shale gas recovery coupled the effect of water flowback[J].Fuel,2017,199:191-205), which will increase the calculation error of the flowback volume of fracturing fluid, thus affecting the prediction of the later productivity of gas wells

Therefore, the calculation method of fracturing fluid flowback in fractured sandstone gas reservoirs has a certain degree of insufficiency, which is not conducive to a large number of field practice

Images