塔河油田碳酸盐岩缝洞型油藏大型复合酸压选井优化论证

Well selection optimization verification of large scale compound acid fracturing in carbonate fracture-cavity reservoir in Tahe oilfield

大型复合酸压是塔河油田针对碳酸盐岩缝洞型油藏常规酸压未建产或产能低的油井提出的一项新型重复酸压改造技术。该技术提高或恢复了部分低产低效及未建产井产能,增油效果明显,但存在一定的差异。在系统分析大型复合酸压井前期油藏特征和酸压效果基础之上,提出了大型复合酸压的地质选井原则。分析认为,高效大型复合酸压井主要选择位于油气富集有利部位、地震属性特征较好(振幅变化率强、反射体规模较大)、前期酸压显示未有效沟通的储集体、生产能量不足且产能较低(累产低)、注水替油效果不佳的井,同时在具有前述地质特征条件下距储集体中心距离较大的井优先选择。

The large scale compound acid fracturing is a new type of acid-refracturing treatment technology propounded for the wells with no or low potential production after conventional acid fracturing in carbonate fracture-cavity reservoir in Tahe Oilfield. The new technology has made the production of few no potential wells or low production and low inefficiency wells promoted or recovered, and the whole effect of production enhance is evidence with some difference. Based on the systematic analysis on previous features of reservoir and acid-fracturing effect before large scale compound acid fracturing, this paper optimizes and proposes the geological well selection principle for large scale compound acid fracturing. The analysis results indicate that the wells for efficient large scale compound acid fracturing should be located in these places, where the favorable positions of oil and gas is accumulated, or seismic attribute characteristics are better than others（high change rate amplitude or large scale of reflect body）; besides, the reservoirs which have no effectively connection during the past conventional acid fracturing and wells with insufficient energy, low production（low cumulative production）poor effect water-flooding are also suggested. Last but not least, the wells should be primarily selected which are under the above mentioned geologic condition with further far distance from the centre of reservoir.