Research On Wu Bao Chang Low Permeability Gas Reservoir Development Adjustment Scheme

Located at the edge of the Chuandong Tectonic Zone,the low permeability gas reservoir of the Shaximiao Formation in the Wubaochang Block is dominated by low pore-low permeability.Its reservoir mobilization is difficult,the dynamic characteristics of the gas reservoir are not well understood,and the development potential target is not clear.Therefore,in this paper,based on the static and dynamic data of the block and using various gas reservoir engineering methods,the decreasing production law,production capacity and reserve utilization status of single wells and blocks are investigated;a combination of gas reservoir engineering and numerical simulation is used to clarify the remaining gas distribution law and propose technical countermeasures for development adjustment.The author designed the development adjustment scheme,predicted the development index,and preferred the implementation plan.The work accomplished in this paper and the results obtained are as follows.Combined with the production dynamics and monitoring information of the area,this paper carried out research on capacity evaluation,production decreasing law,dynamic reserve calculation and analysis based on the understanding of geological characteristics of the block.The results show that:the total production capacity of the block is 232.41×10~4m~3/d,and the average production capacity of single well is 10.48×10~4m~3/d;the overall production decreasing of the block is obvious,and the production decreasing speed of some single wells is faster,mainly showing the reconciliation decreasing,and the monthly decreasing rate is 14%on average,and the difference of single wells is large;the current cumulative production is4.60×10~8m~3,and the degree of geological reserve recovery is 29.2%,and the dynamic reserve of the block is 5.58×10~8m~3.The remaining recoverable reserves are 1.73?10~8m~3,mainly distributed in the second section of Sha,which is the focus of the next development and adjustment.In this paper,based on the results of fine geological description and 3D fine geological model of the low-permeability gas reservoir of the Shaximiao Formation in the Wubaochang block,and also combined with the production dynamic information of the area,a numerical simulation model of the gas reservoir was established and history fitting was carried out.The results of the historical fitting study show that the Shaer ~1sub-section is the main layer of the Shaximiao Formation,and its remaining reserves are 6.60?10~8m~3,which is the key layer for the next development and adjustment.The author proposed adjustment measures such as optimizing production allocation and improving development wells for the problems in the block,and designed a total of six sets of development adjustment plans.Numerical simulation technology was used to predict the development index of each option,and Option 5 was finally recommended as the best option,i.e.,a new straight well with an initial production rate of 2×10~4m~3/d was added for development,with a stable production period of 6 years for a single well and a cumulative gas production of0.68×10~8m~3,and the final cumulative gas production of the block was 6.22×10~8m~3.The recoverable reserves of the block increased by 0.65×10~8m~3,and the final recovery rate is 39%compared with the current implementation plan.