海上砂泥互层水平井分段压裂裂缝扩展规律研究
Research on fracture propagation pattern of segmented fracturing in offshore sand-mud interbedded horizontal wells
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- 引用格式:
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罗迪,马逢源,江锚,张士诚,邹雨时,谢明英,刘伟新,冯沙沙.海上砂泥互层水平井分段压裂裂缝扩展规律研究[J].天然气与石油,2025,43(4):92-99.doi:10.3969/j.issn.1006-5539.2025.04.013
LUO Di, MA Fengyuan, JIANG Mao, ZHANG Shicheng, ZOU Yushi, XIE Mingying, LIU Weixin, FENG Shasha.Research on fracture propagation pattern of segmented fracturing in offshore sand-mud interbedded horizontal wells[J].Natural Gas and Oil,2025,43(4):92-99.doi:10.3969/j.issn.1006-5539.2025.04.013
- DOI:
- 10.3969/j.issn.1006-5539.2025.04.013
- 作者:
- 罗迪1 马逢源1 江锚2 张士诚3 邹雨时3 谢明英1 刘伟新1 冯沙沙1
LUO Di1, MA Fengyuan1, JIANG Mao2, ZHANG Shicheng3, ZOU Yushi3, XIE Mingying1, LIU Weixin1, FENG Shasha1
- 作者单位:
- 1. 中海石油(中国)有限公司深圳分公司, 广东 深圳 518067; 2. 中海油研究总院有限责任公司, 北京 100028; 3. 中国石油大学(北京)石油工程学院, 北京 100100
1. CNOOC China Ltd., Shenzhen Branch, Shenzhen, Guangdong, 518067, China; 2. CNOOC Research Institute, Beijing, 100028, China; 3. College of Petroleum Engineering, China University of Petroleum(Beijing), Beijing, 100100, China
- 关键词:
- 海上低渗储层;分段压裂;裂缝扩展;边界元;砂泥互层
Offshore low-permeability reservoirs; Segmented fracturing; Fracture propagation; Boundary element; Sand-mud interbedded
- 摘要:
- 南海东部低渗储量规模巨大,矿场实践表明水平井是进行海上低渗储量规模化开发的有效途径。南海东部低渗储量沉积特征呈现砂泥互层、薄互层等规律,为研究砂泥互层型储层水平井分段压裂水力裂缝扩展规律,采用边界元方法对影响水平井水力裂缝穿层扩展规律的地质因素和工程因素开展了研究分析,同时考虑受应力干扰导致的基质岩石单元的挤压变形,确定了地质因素和工程因素与水力裂缝形态的关系。研究结果表明:建立的水平井分段压裂裂缝扩展模型与现有模型解析解一致性较好,能反映海上砂泥互层型储层水力裂缝扩展规律;地质主控影响因素主要包括隔夹层厚度、储隔层层间应力差,工程主控影响因素包括施工排量;隔夹层厚度和储隔层层间应力差抑制缝高纵向扩展,当储隔层层间应力差超过6 MPa、下伏夹层厚度超过8 m时,裂缝在中部储层中横向扩展;当隔夹层厚度和储隔层层间应力差一定时,排量的提升能促进水力缝高纵向扩展。结论认为,海上低渗储层水力压裂要实现最优改造效果,须采用合理的排量及完井策略,确保水力裂缝缝高合理穿层以达到方案设计水平。研究结果为海上低渗储层水平井储层改造压裂一体化方案设计提供了理论依据和技术支撑。
The scale of low-permeability reserves in the eastern South China Sea is enormous, and field practice has shown that horizontal wells are an effective way to carry out large-scale development of offshore low-permeability reserves. The sedimentary characteristics of low-permeability reservoirs in the eastern South China Sea exhibit sand-mud interbedded and thin interbedded patterns. In order to study the hydraulic fracture propagation pattern of horizontal well segmented fracturing in sand-mud interbedded reservoirs, the boundary element method was used to analyze the geological and engineering factors that affect the hydraulic fracture propagation pattern of horizontal wells. At the same time, the compression deformation of matrix rock units caused by stress interference was considered, and the relationship between different geological and engineering factors and hydraulic fracture morphology was determined. The research results show that: The established horizontal well segmented fracturing fracture propagation model is consistent with the analytical solutions of existing models, and can better reflect the hydraulic fracture propagation pattern of offshore sand-mud interbedded reservoirs; the main geological controlling factors include interlayer thickness and interlayer stress difference, while the main engineering controlling factors include injection rate. The thickness of the interlayer and the stress difference of reservoir-seal pair suppress the longitudinal expansion of the fracture height. When the stress difference of the reservoir-seal pair exceeds 6 MPa and the thickness of the underlying interlayer exceeds 8 m, the fracture expands laterally in the middle reservoir; when the thickness of the interlayer and the stress difference in reservoir-seal pair are constant, the increase in injection rate can promote the longitudinal expansion of hydraulic fractures. The conclusion is that in order to achieve the optimal transformation effect of hydraulic fracturing in offshore low-permeability reservoirs, it is necessary to adopt a more rational injection rate and completion strategy to ensure that the hydraulic fractures penetrate the layer at a reasonable height to achieve the design level of the plan. The research results provide theoretical basis and technical support for the design of integrated fracturing schemes for horizontal well reservoir transformation in offshore low-permeability reservoirs.
