鄂尔多斯盆地东缘煤系地层合层压裂工艺研究
Research on combined-layer fracturing technology of coal-measure strata in the eastern margin of the Ordos Basin
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- 引用格式:
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寇春松,郭布民,安琦,陈玲,郝鹏灵,王达,曹金豪,张世鹏.鄂尔多斯盆地东缘煤系地层合层压裂工艺研究[J].天然气与石油,2025,43(6):99-108.doi:10.3969/j.issn.1006-5539.2025.06.013
KOU Chunsong, GUO Bumin, AN Qi, CHEN Ling, HAO Pengling, WANG Da, CAO Jinhao, ZHANG Shipeng.Research on combined-layer fracturing technology of coal-measure strata in the eastern margin of the Ordos Basin[J].Natural Gas and Oil,2025,43(6):99-108.doi:10.3969/j.issn.1006-5539.2025.06.013
- DOI:
- 10.3969/j.issn.1006-5539.2025.06.013
- 作者:
- 寇春松1 郭布民1 安琦2 陈玲1 郝鹏灵1 王达1 曹金豪1 张世鹏1
KOU Chunsong1, GUO Bumin1, AN Qi2, CHEN Ling1, HAO Pengling1, WANG Da1, CAO Jinhao1, ZHANG Shipeng1
- 作者单位:
- 1. 中海油田服务股份有限公司, 天津 300450; 2. 中联煤层气有限责任公司, 北京 100015
1. China Oilfield Services Limited, Tianjin, 300450, China; 2. China United Coalbed Methane Corporation Ltd., Beijing, 100015, China
- 关键词:
- 煤砂合压;煤系地层;均匀改造;缝口暂堵;延伸压力
Coal-sand combined fracturing; Coal-measure strata; Uniform stimulation; Temporary plugging at fracture mouth; Fracture propagation pressure
- 摘要:
鄂尔多斯盆地东缘含煤地层具有多层系交互赋存、纵向薄层(夹层)发育的特点,多层合压是实现煤系气经济高效开发的必然要求。多层合压成功的关键取决于各层位的进液速率及进液量,当前合层压裂液量分配和改造程度不明,各储层设计改造程度预测产气量与实际产气效果存在较大偏差,难以实现储层精准改造。针对深部煤层气与致密气多层合压时各储层改造需求的差异性、砂液量及排量的特殊性、工艺的不确定性等问题,通过现场施工数据、理论计算、数值模拟等方式,得到深煤层、临煤致密气层延伸压力及差值、不同排量及射孔参数下的进液分布和工艺参数优化,建立煤系地层多层合压的工艺参数计算模型。结果表明:鄂尔多斯盆地东缘神府—临兴区块深煤层裂缝延伸压力高于临煤致密气层,延伸压力差在2.0~7.0 MPa;在排量20 m3/min、延伸压力差5.0 MPa、射孔直径11 mm的条件下,低延伸压力层段(致密气层)射孔数超过55孔时,高延伸压力层段(深煤层)将无法起裂,射孔数量范围应为临界射孔数(55孔)的30%~70%;根据延伸压力差,以射孔分配精准调控致密气层进液速率,达到设计缝长(200~250 m)后缝口暂堵转向压裂深煤层,优化各层压裂缝长,避免出现改造程度失控的情况。研究结果为鄂尔多斯盆地神府—临兴区块的煤层气、致密气资源高效开采提供了设计理论依据。
The coal-bearing strata in the eastern margin of the Ordos Basin exhibit characteristics of multi-strata interactive occurrence and vertical thin layers(interlayers). Multi-layer combined fracturing(MLCF) is essential for the economical and efficient development of coal-measure gas. The success of MLCF depends on the fluid injection rate and volume into each layer. However, current challenges include unclear fracturing fluid distribution and stimulation effectiveness across layers, leading to significant deviations between predicted and actual gas production, which hinders precise reservoir stimulation. Addressing issues such as differential stimulation requirements for deep coalbed methane(CBM) and adjacent tight gas layers, unique sand-fluid volume and pumping rate demands, and process uncertainties, this study utilized field data, theoretical calculations, and numerical simulations to analyze fracture propagation pressures and their differentials between deep coal seams and adjacent tight gas layers, fluid distribution under varying pumping rates and perforation parameters, and process optimization. A process parameter calculation model for coal-measure MLCF was established. Results show that the fracture propagation pressure of deep coal seams in the Shenfu-Linxing area of Ordos Basin exceeds that of adjacent tight gas layers, with a differential of 2.0~7.0 MPa. Under conditions of a pumping rate of 20 m3/min, a propagation pressure differential of 5.0 MPa, and a perforation diameter of 11 mm, the high-pressure layer(deep coal seam) fails to initiate fractures when the low-pressure layer(tight gas) has over 55 perforations. The perforation allocation should range between 30% and 70% of the critical number of perforations(55 perforations). By precisely regulating perforation allocation to control fluid entry into tight gas layers and implementing temporary plugging at the fracture mouth after achieving the target fracture length(200~250 m), effective stimulation of deep coal seams can be achieved, avoiding uncontrolled fracture growth. These findings provide a theoretical foundation for optimizing the efficient co-development of CBM and tight gas resources in the Shenfu-Linxing area of the Ordos Basin.
