The Research Of Fracturing Technology Optimize In Su-53 Block

Block 53 of Sulige gas field is located in the northwest of Sulige gas field.It is a typical"four low" lithologic gas reservoir with low porosity,low permeability,low pressure and low abundance.The reservoir heterogeneity is strong and brings great difficulties to fracturing reconstruction,and the effect of pre-fracturing transformation is not ideal.Therefore,after investigating reservoir geological conditions and gas reservoir characteristics,combined with the data of pre-fracturing post-evaluation,process effect analysis and development effect analysis in this area,it is concluded that the main difficulties of fracturing reconstruction in this area are reservoir vulnerability,weak pertinence of fracturing optimization design in horizontal wells,high effective extension of multi-thin fracturing and high difficulty of fracture control.In order to solve these problems,this paper carries out low damage fracturing technology research experiments for low permeability gas reservoirs,optimizes fracturing parameters for horizontal wells in heterogeneous reservoirs,and carries out regional longitudinal multi-thin layer fracturing technology optimization by using field actual samples and data,and draws the following conclusions:(1)Fracturing fluid damage in this area is mainly caused by water phase and residue damage.The residue damage is mainly caused by formation of filter cake to block fracture wall and filling support fracture,resulting in low overall backflow rate.In order to further improve the backflow rate,the high-efficiency backflow technology,which combines segmental gel breaking,mixed fibre injection and liquid nitrogen injection,can be used to reduce reservoir damage.(2)Block fracturing design has poor pertinence.By establishing a comprehensive geological model,considering the start-up pressure gradient and dividing the seepage unit,an optimization method for fracture parameters of horizontal wells in heterogeneous reservoirs is formed,and the corresponding construction parameters are optimized.(3)There are many longitudinal thin beds in the block,and it is difficult to control fractures.Continuous in-situ stress profiles are established by logging method,and then models are established by numerical simulation software.The optimal parameters of fracture control and high-pressure fracturing technology in vertical and horizontal sections are obtained by simulation.This paper puts forward targeted technological measures and optimizes the matching of optimal fracturing parameters,and finally forms the key technology of "four low" reservoir fracturing in Sulige 53 Block,which provides guidance and reference for subsequent reservoir reconstruction measures in Sulige 53 Block.