煤层气井网密度及井距优化是影响煤层气产量和经济效益的重要因素,井网密度及井距的设计优化是煤层气开发方案的重要组成部分。当前对于煤层气开发井距的研究大多单一考虑产能因素或者是经济因素,对于二者综合评价研究较少。为探究煤层气开发井网密度和井距的最优方案,并综合评价煤层气井的产能与经济效益,以韩城北区块为研究对象,基于区块基本地质条件和煤储层物性资料,确定了煤层气开发适用的井网样式和井网方位。通过经验对比法、单井合理控制储量法、经济极限井距法、规定单井产能法和经济极限井网密度法计算并讨论了韩城北区块煤层气开发井网密度和井距部署方案。利用煤层气产能数值模拟软件Comet3,模拟和评价了不同井距开发方案下的产能,并采用折现现金流法进一步从经济评价角度优化了煤层气开发井网密度。结果显示,韩城北区块煤层气开发适用的井网样式为矩形井网;井网方位为NE49°;数值模拟结果表明,当井距为200 m×250 m 时煤层气井稳产期产能最高,累计产量最多;依据1 km2 不同井距布井方案的经济评价对比显示,当井网密度大于10 口/km2 时,该区块煤层气开发具有经济效益,其中井网密度为20 口/km2 即井距为200 m×250 m 的方案内部收益率为11.27%,净现值为1 437 万元,投资回收期为7.49 年,经济指标最优。综合分析认为,韩城北区块最佳开发井网密度为20 口/km2,最佳井距方案为200 m×250 m。

Coalbed methane (CBM) well network density and well spacing optimization are important factors affecting CBM productionand economic efficiency, and are important components of CBM development programs. At present, most of the researches on well spacingfor CBM development only consider productivity factors or economic factors, but there are few comprehensive evaluation studies on them. In order to explore the optimum scheme of well pattern density and well spacing for CBM development, and to comprehensivelyevaluate the productivity and economic benefits of CBM wells, based on the basic geological conditions of the Hanchengbei block andphysical data of coal reservoir, the well pattern and well pattern orientation suitable for CBM development are determined in this paper.Through experience comparison method, single well reasonable control reserve method, economic limit well spacing method, specifiedsingle well productivity method and economic limit well pattern density method, the well pattern density and well spacing deploymentscheme for CBM development in Hanchengbei block are calculated and discussed. Using numerical simulation software Comet3 of CBMproductivity, the productivity under different well spacing development schemes is simulated and evaluated, and the density of well patternfor CBM development is further optimized from the perspective of economic evaluation by discounted cash flow method. The resultshows that the suitable well pattern for CBM development in Hanchengbei block is rectangular well pattern. The well pattern orientation isNE49°. The numerical simulation results show that when the well spacing is 200 m×250 m, the stable production period productivity ofCBM well is the highest and the cumulative production capacity is the highest. According to economic evaluation and comparison of differentwell spacing schemes in 1 km2, when well pattern density is more than 10 wells/km2, the development of CBM in this area has economicbenefits, where well pattern density is 20 wells/km2 and well spacing is 200 m×250 m scheme is 11.27%, the net present value is14.37 million yuan, and the payback period of investment is 7.49 years, the economic index is the best. Comprehensive analysis shows thatthe best development well pattern density of Hanchengbei block is 20 wells / km2, and the best well spacing scheme is 200 m×250 m。