水平井可控穿层压裂技术在低渗透油田的应用

Application of Controllable Translayer Fracturing Technology for Horizontal Well in Low Permeability Oilfields

大庆长垣外围油田属于低产、低渗透和低丰度的"三低"油田,储量动用难度大,直井等常规技术手段无法实现有效动用。水平井可控穿层压裂技术是一种纵横兼顾的技术,可以全部动用地质储量,且不会造成储量损失。2012年在油水关系简单的古龙南地区茂15-1区块开辟水平井规模应用示范区,部署22口水平井,通过开展葡萄花薄互层水平井可控穿层压裂技术研究,探索外围油田难采储量的经济有效开发方式。经过理论研究,形成穿层压裂判断标准,通过优化压裂施工参数,确保穿层压裂成功。茂15-1区块完成水平井压裂12口井,其中穿层压裂应用5口井,初期平均单井日产油12.1t/d,是周围直井的4.5倍。统计可对比的10口井,其中常规压裂的5口水平井初期平均单段日产油1.9t/d,穿层压裂的5口水平井初期平均单段日产油2.3t/d。水平井可控穿层压裂技术实现了少井高产和难采储量的整体动用,在保证单井产能达到设计指标的情况下,平均单井少压4段,压裂费用降低了42.6%。

Oilfields around Daqing placanticline belong to low productivity,low permeability and low abundance ＂three low＂ oilfields.The reserves are hard to be produced by the vertical wells and other conventional tech-nologies.Controllable translayer fracturing for the horizontal well is a kind of balance technology,which can make all geological reserves be produced with no reserves loss.Demonstration area of scale application of the horizontal wells was built in Mao 15-1 block,Gulongnan area with simple oil-water relationship in 2012.Controllable translayer fracturing is complemented in 22 horizontal wells in thin interbed of Putaohua so as to probe economic and effective development scheme for difficult-to-produce reserves in oilfields around Daqing placanticline.After theoretical study,translayer fracturing criterion is established.Optimizing fracturing operation parameters may ensure the success of the translayer fracturing.Twelve horizontal wells were fractured in Mao15-1 block.Among them,the translayer fracturing was made in 5 wells.Their initial average daily oil produc-tion of single well was 12.1t/d,which is 4.5 times of the vertical wells around.Ten wells are compared by statistic data.Initial average daily oil production of single interval was 1.9t/d and 2.3t/d in five horizontal wells by common fracturing and in those by translayer fracturing respectively.The technology of controllable translayer fracturing for the horizontal well may achieve high yield with less wells and overall use of the dif-ficult-to-produce reserves.Under the condition of achieving designed index of single well productivity,four intervals may not be fractured averagely and cost of the fracturing decreased by 42.6%.