摘要
含煤地层煤层气、致密砂岩气等非常规天然气共探共采是保护天然气资源和提高开发综合效益的重要途径。基于鄂尔多斯盆地临兴地区煤系储层地质条件分析,采用煤系砂岩和煤层层间无窜流双层地质模型,开展了煤系砂岩气与煤层气共采可行性的数值模拟研究,探讨了两气共采效果的影响因素,建立了基于产量贡献率的共采综合评价模型,确定了煤层气与砂岩气共采的参数门限。结果显示,研究区地质构造简单,广覆式生烃的煤系烃源岩与大面积分布的致密砂岩储集层、煤储层及泥岩储层相互叠置,有利于煤系气体成藏;研究区煤系页岩气生产潜力较小,共采以砂岩气和煤层气为主。随着煤系砂岩储层渗透率、压力系数、厚度和孔隙率增加,10年砂岩气产量累计贡献率呈增加趋势;随着砂岩储层含水饱和度升高,10年砂岩气产量贡献率呈下降的趋势;煤层气与砂岩气适合共采综合指数介于8×10^(-7)~4.44之间,高于4.44适合砂岩气单采,低于8×10^(-7)适合煤层气单采。临兴地区L-3井(8+9号煤)、L-10井(4+5号煤)、L-1井、L-4井、L-6井及L-9井的2层主力煤煤层气与致密砂岩气适合共采,而其他井适合致密砂岩气单采。
Joint mining of unconventional gas resources in coal series,including coalbed methane（CBM）and tight sand gas,are an important way to protect natural gas resources and improve the efficiency of development.Based on geological conditions of coal series in Linxing Block of Ordos Basin,a numerical simulation study was conducted to discuss the feasibility of co-mining of coal series sandstone gas and coalbed methane using double-layer geological model without inter-flow between layers.The paper discussed the influence factors for affecting co-mining,and created a comprehensive evaluation model according to the contribution rate,and confirmed the threshold value of reservoir parameter.The results showed that the geological structure of the study block was simple,the widely covered hydrocarbon source of coal stacks each other with large-scale sandstone reservoirs,coal reservoir and shale reservoir,which was favorable to gas reservoir formation.The shale gas production potential in the study area was low,which were mainly composed of sandstone gas and coalbed methane.With the increase of permeability,pressure coefficient,thickness and porosity of coal series sandstone reservoir,the cumulative contribution rate of sandstone gas accumulation in 10 years increased,but with the increase of water saturation of sandstone reservoir,it decreased.In order to realize the co-mining of coal series sandstone gas and coalbed methane,the co-mining composite index should be 8×10^（-7）-4.44.The value above 4.44 is suitable for sandstone gas single production,while under 8×10^（-7） is suitable for coalbed methane single mining.These wells were suitable for comining that No.8＋9coal of L-3,No.4＋5coal of L-10,No.4＋5coal and No.8＋9coal of L-1,L-4,L-6and L-9,and other wells were suitable for sandstone gas single mining.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2017年第3期479-487,共9页
Natural Gas Geoscience
基金
国家科技重大专项项目(编号:2016ZX05066-01-04)
国家自然科学基金项目(编号:41302131)
华北油田分公司博士后项目(编号:2013E-2208-2015-M08)联合资助
关键词
临兴地区
煤系砂岩气
煤层气
影响因素
共采门限
Linxing Block
Coal series sandstone gas
Coalbed methane
Effect factor
Threshold of co-mining
