关键词:

深层页岩气, 分段多簇压裂, 应力敏感, 裂缝导流能力, 产能预测

Abstract:

It is difficult for deep shale fracturing to create complex fractures and the fracture conductivity fails quickly，resulting in rapid decline in production. To clarify the impact of hydraulic fracture conductivity on deep shale gas production，a propped fracture conductivity computational model and a mathematical model for predicting the productivity of deep shale gas were established based on the test data on the conductivity of deep shale fractures，while also considering the effects of closure stress，proppant concentration and particle size on the conductivity. The production data of deep shale gas in the southern Sichuan were used to conduct historical matching and prediction on the model，which verified the accuracy of the model. The effects of proppant concentration，closure stress and proppant particle size on the production of deep shale gas were studied and analyzed. The results show that the stable production time and  Estimated Ultimate Recovery（EUR） of deep shale gas wells can be improved by increasing the proppant concentration and selecting proppants with smaller particle size，with the optimal proppant concentration falling between 1-2 kg/m²；when the closure stress was increased from 80 MPa to 110 MPa，the stable production time was reduced by 40%；the optimum proppant particle size is 40/70 mesh due to the combined effect of proppant particle size and the half-length of propped fracture. The results provide a theoretical basis for the fracture conductivity design and production forecast of deep shale gas reservoirs.

Key words:

"> deep shale gas, staged multi-cluster fracturing, stress sensitivity, fracture conductivity, production forecast