双重介质储层压裂技术在河南油田梨树凹区块中的应用

Application of Dual-medium Reservoirs Fracturing Technology in Block Lishuwa of Henan Oilfield

梨树凹区块属中低渗、中低孔储层,天然裂缝发育不均,属双重介质储层,压裂时易产生早期砂堵。压裂施工所形成的人工裂缝极易沿天然裂缝延伸形成多裂缝,难以形成具有一定缝宽的主裂缝,因压裂液过量滤失导致早期砂堵,制约了该区的有效开发。针对梨树凹储层特征应用高粘压裂液体系、"一升一降"变浓度压裂液优化设计技术、前置粉陶多级降滤技术及斜线加砂技术,现场应用效果显著,成功地解决梨树凹区块压裂时易发生早期砂堵的问题,保证了双重介质储层的有效开发。

Block Lishuwa was a mid-low permeability,porosity reservoir with uneven natural fracture development and it belonged to dual medium reservoir,where early sand plug was easily produced in fracturing.The artificial cracks formed by fracturing were easily expanded along the natural fractures to form a multi-fractures,and was difficult to form a certain width of main fractures.Due to the excessive loss of fracturing fluid,it would result in a early sand plug to restrict the effective development of the area.In allusion to the reservoir characteristics of Lishuwa Area,a viscous fracturing fluid system and the technology of 'a rise and a fall ' optimal fracturing fluid design of variable concentrations the multi-stage fluid of pre-ceramic and slash sand were all applied.The effect of field application is significant,the problems of early sand plug are successfully solved and the effective development of dual-medium reservoir is ensured.