Study on fracturing fluid return pattern and production characteristics of shale gas wells

Abstract

We innovatively propose a research method through micro-experiment + macro-measurement, combined with onsite proppant return test. This method can solve the problem of unclear impact of the return shut-in time, return rate control and return effect on production. We carried out a specific applied research for Fuling shale gas Jiangdong block, specifically determined the mineral composition, overburden pressure physical properties before and after fracturing fluid percolation, the changing law of resistance environment of gas production channel inside the reservoir before and after fracturing fluid percolation, and explored the settlement problem of proppant’s size, type and nature in the fracture through the situation of sand return. This study concludes that the reservoir testing process can be divided into pure fluid production stage, gas breakthrough stage, and stable production stage. The optimal contact time between shale and fracturing fluid promotes the hydration of clay minerals to produce microfractures and the formation of a complex network of intercommunicating seams facilitated by external dynamics, which promotes gas production. And the wrong return after fracturing will affect the hydraulic fracture conductivity.