| The tight sand gas reservoir with low porosity and low permeability characteristics has no performance in nature state,so only under reservoir transformation technologies,such as hydraulic fracturing,can it be developed industrially.As the poor effect of conventional fracturing technology,there is an urgent need to develop a new fracturing technology..In recent years,the tight sand gas can be developed by the key technology of volume fracturing.The SRV is an important parameter to evaluate the reservoir capacity after volume fracturing,and crucial to the effect of fracturing construction.Currently,the domestic and overseas research of the calculation procedure of SRV is relatively less and partial.The calculation of tight sand gas’ s capacity after volume fracturing is also based on which in conventional fracturing technology,without proper consideration of SRV.On the ground of lots of investigation and survey,this paper simplifies the discrete fracture network,takes tight sand gas reservoir’s physical property and fracturing construction parameters into consideration,establishes the physical and mathematical model of SRV,and based on this,develops a program which can predict the SRV.This program is used to study and analyze the effect of aspect radio,fracturing time,comprehensive leak-off coefficient,the thickness of reservoir,horizontal stress difference and effective elasticity modulus on the SRV,optimizes construction parameters with the target of SRV.On the basic of SRV’s physical model,the capacity calculation model of tight sand gas reservoir with complex fracture network is built.This paper takes fracture’s complexity into consideration,deduces capacity calculation formula of tight sand gas reservoir with complex fracture network,studies the influence of induced fracture’s shape,fracture’s number,fracture’s length,fracture’s conductivity,secondary fracture’s shape,reservoir’s permeability and reservoir’s thickness on reservoir capacity,uses orthogonal experiment analytical method and gray relevance theory to study multi-factors’ influence on the capacity of horizontal well after volume fracture in tight sand gas reservoir,and primary and secondary relationship between factors,and optimizes the parameters of fracture.The researching results have an important guiding meaning for the design of volume fracturing construction in tight sand gas reservoir. |
