Feng Xiaoxu, Liao Xinwei
China University of Petroleum Beijing, 18 Fuxue Road, Beijing, 102249 China.
University of Utah, Salt Lake City, Utah 84112, United States.
ACS Omega. 2020 Feb 13;5(7):3755-3762. doi: 10.1021/acsomega.9b04480. eCollection 2020 Feb 25.
Compared to the shale gas and coalbed methane in China, tight gas has been recently considered as a priority in the exploration and exploitation of unconventional gas resources. In the development of a tight gas field, how to enhance the gas recovery is a prevalent topic. Unlike the conventional gas reservoir, the ultimate gas recovery is not only determined by the geological characteristics but is also affected by other factors such as well drainage area and well spacing design. For tight sandstone reservoirs, the gas recovery can be improved by increasing the drainage area. Moreover, the well drainage area is closely associated with well spacing. Therefore, effective drainage area estimation and well spacing optimization are essential aspects for tight gas exploitation. In this paper, a new optimization workflow is established, which combined dynamic analysis and numerical simulation techniques. First, through interference well test results and production data dynamic analysis, the total gas production can be expressed and predicted. Then the well density can be optimized by the economic evaluation method. Meanwhile, a numerical model is built up to determine the optimal well spacing. This new optimization workflow can provide guidance to the operators of tight gas fields where the interference well test results are available and several years of production data are collected. Furthermore, in the case of the Sulige gas field, the single well drainage area is estimated and the optimal well pattern is obtained by the established approach. The results indicate that the well pattern of 500 m × 600 m is most reasonable for the pilot gas field.
与中国的页岩气和煤层气相比，致密气最近被视为非常规天然气资源勘探开发的重点。在致密气田开发中，如何提高气藏采收率是一个普遍关注的问题。与常规气藏不同，最终气藏采收率不仅取决于地质特征，还受其他因素影响，如井控面积和井距设计。对于致密砂岩气藏，可通过扩大控气面积提高采收率。此外，井控面积与井距密切相关。因此，有效控气面积计算和井距优化是致密气开发的重要环节。本文建立了一种新的优化流程，结合了动态分析和数值模拟技术。首先，通过干扰试井结果和生产数据动态分析，可表征和预测气藏总产量。然后采用经济评价方法优化井网密度。同时，建立数值模型确定最优井距。这种新的优化流程可为有干扰试井结果和多年生产数据的致密气田经营者提供指导。此外，以苏里格气田为例，采用所建立的方法计算单井控气面积并得到最优井网。结果表明，对于试验区气田，500m×600m的井网最为合理。
