A Study On Development Project Adjustment Of S26 Block

The design of development plan and its adjustment scheme is so crucial for gas field development that reasonably designing a set of field development project or development.adjustment scheme can effectively reduce the investment cost, maximize the overall development efficiency of gas field and increase economic benefits. S26 block in Sulige gas field has already entered the production decline stage. Although it has rich gas reservoir reserves, but the reservoir physical property is poor, a large amount of ultra-low permeable reservoirs are difficult to be exploited.In order to maximize gas recovery degree of the block, it is urgent to design reasonable development plan adjustment countermeasures.First of all, this paper analyzed the production performance of S26 block such as current exploiting status, horizontal well production characteristics, liquid production in gas wells and productivity decline condition by using the reservoir engineering method. On this account,the dynamic characteristics of gas reservoir was acquainted,and the main problems existing in the current block mining are proposed.Then, this paper evaluated dynamic reserves by instability analysis method and flow material balance method,so as to determine the gas wells which qualified the conditions of actualizing measures to increase production, and provided a basis for developing remaining gas cost-efficiently. Moreover, based on the dynamic and static data obtained during the process of gas reservoir production, combined the study on geological properties and dynamic features, a precised reservoir geological model is established. Eventually, the numerical simulation model was build to make simulation and prediction by using different adjustment plans.And then the most optimal solution-can be selected by comparing the predicted results, which can provide technical support to further increase of the ultimate recovery.Based on the analysis of the production data, and combined with the understanding of gas reservoir engineering and geological research,3 sets of project adjustment containing infill well pattern, pressurization and combining plan were designed. By comparing the results predicted by numerical simulation, it turned out that the infill well pattern program with 219.8×104m3 of daily gas production, which stable production period is 5.2 years and recovery degree can be increased by 2.59% at the end of forecast period.The pressurization scheme can improve the prediction of the final gas recovery by 4.72% and reached 25.14%. Generally, the optimal adjustment scheme including pressurization, fill perforation for low production wells and pattern infilling was ultimately recommended. In this program,219.8×104m3 of daily gas production can maintain for 8.4, and the final prediction recovery increased by 12.9 percentage points, which achieved 33.32% at the end of forecast period, and the cumulative gas production is 231.92×108m3, which improved by 89.92×108m3 compared with the basic program.