ABSTRACT
The reservoir of Benxi Formation of Carboniferous in Shenfu block is highly heterogeneous and belongs to low porosity and low permeability coal measure sandstone. The average porosity is 4.2%, the permeability is 0.35 mD, and the natural gas production of the gas well is low. The production needs to be obtained through fracturing. Fracturing reconstruction is an important measure for exploration and development in this area, but the fracturing effect of some wells is poor in recent years. Therefore, targeted research on fracturing technology and supporting technologies is needed to improve the drilling success rate and fracturing effect. In this paper, the experimental evaluation of rock mineral composition and rock mechanics is carried out by means of full core analysis and X-ray diffraction. The research shows that the young's modulus of the Benxi Formation reservoir is 26300 MPa ~ 28200 MPa, the Poisson's ratio is 0.24 ~ 0.26, and the lithology is mainly quartz sandstone, indicating that the rock is brittle, the formation is relatively easy to open (when the in-situ stress is not particularly high, but it is not easy to open in deep wells in the western region), and the calculated brittleness index is 50 ~ 52%. The minimum principal stress is 50.7 ~ 54.7 MPa, the maximum principal stress is 69.8 ~ 74.1 MPa, the maximum and minimum stress difference is 19.1 ~ 19.4 MPa, and the in-situ stress difference coefficient is 0.35 ~ 0.38, which is not easy to form a complex fracture network. The stress difference of the interlayer is 6.1 MPa and that of the lower interlayer is 8.4MPa. The nature of the interlayer is general. High fracture control technology shall be adopted for fracturing to prevent excessive fracture extension. Based on the reservoir characteristics of the Benxi Formation, the fracturing process is optimized, and finally, a fracturing technology suitable for the study area is formed.
