Study On Optimization Of Volumetric Fracturing Crack Network In Unconventional Shale Gas Formation

Shale gas formation usually have the geological characteristics of low porosity and low permeability in performance from the author classifies and large areas of continuous accumulation phenomenon.In the light of the shale reservoir matrix permeability is very low,but with the help of a large-scale fracturing technology to achieve industrial air flow,and shale gas can develop smoothly,fracturing construction is the most important link.Shale gas reservoir development process through in North America area,expounds the pressure before the evaluation technology,shale reservoir fracturing cracks key technology present situation and the latest progress,such as well completion technology and the technology of horizontal well fracturing.On this basis,through the development of shale gas reservoir fracturing test applied research,has established three test fracturing process,complete the induction small test fracturing overall scheme optimization design and puts forward the general principles of induction test fracturing design.And perfected the perforating optimization and cluster perforation scheme optimization method,the distribution patterns of different cracks is optimized and the fracture parameters optimization design model was established,combining network fracture fracturing design induced stress field and fracture to design method is proposed,and finally completed the shale gas reservoir fracturing optimization design procedures and the basic flow.In addition,forming low molecular drag reduction hydraulic fracturing fluid system,strong adaptability,can meet the different needs of shale oil and gas fracturing.Established the evaluation G function diagnosis chart,pressure after analysis put forward the conventional filtration,low filtration,micro fracture development,microfracture development,during the process of fracturing induced sewing,induced branch crack type filtration five types,is used to determine formation fracture development characteristics.Optimizing the key area of shale gas well,combining with the previous analysis,carried out aiming at single well fracturing design optimization,will increase net pressure induced cracks steering technology and the corresponding theoretical model applied to X2 well design and field test,the well construction process is successful,compound with optimal efficiency of drag reduction agent through the liquid and the fracturing construction inspection,the drag reduction performance shows good(drag reduction rate was 78%),can realize the geological pressure,do not sand plug and can vent.