致密油水平井重复压裂技术及现场试验

REFRACTURING TECHIQUE AND ITS FIELD TEST FOR THE HORIZONTAL WELL IN THE TIGHT OIL

大庆致密油水平井体积压裂取得了较好效果,但是产量递减较快,部分水平井目前产量较低。为改善这种生产现状,开展了致密油水平井重复压裂现场试验。首先结合地质、工程及生产情况,通过聚类分析方法优选了P34-H6井为重复压裂目标井。利用油藏数值模拟技术评价井间剩余油分布特征,优化补压新缝,采用水平井双封单卡分段压裂工艺对新缝依次进行改造。现场完成压裂施工16段,井下微地震监测结果显示重复压裂后裂缝波及体积明显增大,重复压裂后初期日产液量27.7 t,日产油量7.7 t,取得了较好的增产效果。P34-H6井重复压裂的成功实施对于致密油藏水平井提高开发中后期效果具有重要意义。

Much better effects have achieved for the horizontal-well volume fracturing in Daqing tight oil,but the production declines rather seriously,and moreover parts of the horizontal well＇s productions are rather lower at present. In order to improve the current conditions of the production,the field test of the horizontal-well refracturing in the tight oil was conducted. At first,integrating with the geological,engineering and production situations,with the help of cluster analyzing method,Well P34-H6 was optimized to be the target well of the refracturing. By means of the numerical simulating technique of the oil reservoir,the distribution characteristics of the remained oil among the wells were evaluated,the added-fractured new crack was optimized,and furthermore the new fractures were reformed and retreated one-by-one by the staged fracturing technology with double packers and single clip for the horizontal well. 16 intervals were fractured in the field,the downhole microseismic monitored results show that the fracture swept volume after the refract was increased obviously,the initial liquid production was up to 27. 7 t per day and the oil output was up to 7. 7 t per day,thus much better incremental effects were achieved. The successful operation of Well P34-H6 refracturing possesses important significance for enhancing the effects in the middle and late-stage developments of the horizontal well in the tight oil reservoir.