压裂煤层气井生产动态模拟及产出特征分析

发布时间：2018-05-26 04:07

本文选题：煤层气 + 压裂　；参考：《内蒙古石油化工》2016年10期

【摘要】：煤层气是一种重要的非常规清洁能源。分析和总结煤层气井排采数据发现生产动态与传统认识并不一致。在Warren-Root模型基础上,综合考虑煤层气的解吸、扩散及渗流规律,建立了压裂煤层气井三维两相的生产动态模拟数学模型,然后采用IMPES方法和逐次线松弛方法求取数值解。通过数值模拟结果分析压裂煤层气井的生产特征,提出压裂煤层气井产气特征通常应包含四个阶段——单相水流阶段、非饱和水相单相流阶段、气/水两相流阶段和饱和气体单相流阶段。在日产气量曲线上表现为有两个峰值产量出现,气相相对渗透率上升越快,第二个产量峰值越高,出现得也越早,但产量递减也相对较快;第二产量峰值只在气相相对渗透率上升较快情况下出现。否则,不会出现第二个产量峰值,而会出现一段较长的稳产阶段。这对于指导现场进行科学排采及高效开发有重要意义。
[Abstract]:Coal bed methane (CBM) is an important unconventional clean energy source. Analyzing and summarizing the production data of coalbed methane wells and finding that the production performance is not consistent with the traditional understanding. On the basis of Warren-Root model and considering the law of desorption, diffusion and percolation of coalbed gas, the mathematical model of three-dimensional two-phase production simulation of fractured coalbed gas well is established, and then the numerical solution is obtained by using IMPES method and successive line relaxation method. By analyzing the production characteristics of fractured coalbed gas wells by numerical simulation results, it is proposed that the gas production characteristics of fracturing coalbed gas wells should consist of four stages: single phase flow stage, single phase flow stage with unsaturated water phase, and single phase flow stage with unsaturated water phase. Gas / water two phase flow stage and saturated gas single phase flow stage. In the daily gas yield curve, there are two peak yields, the faster the gas phase relative permeability increases, the higher the second peak value is, and the earlier it appears, but the faster the production decline. The peak of the second output occurs only when the gas phase relative permeability increases rapidly. Otherwise, there will not be a second peak, but a longer period of stable production. This is of great significance for guiding the scientific extraction and high-efficiency development on the spot.
【作者单位】：陕西延长石油(集团)有限责任公司研究院;陕西延长石油(集团)有限责任公司油气勘探公司石油勘探开发部;
【分类号】：TE37

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