吴起油田白河区侏罗系油藏增产措施

Production Stimulation of Jurassic Reservoir in Baihe Area of Wuqi Oilfield

吴起油田白河区侏罗系油藏绝大部分为边底水发育的鼻状隆起的构造油藏,天然能量相对较充足,初期一般能获得较高的产能。但油层的非均质性较为突出,存在隔层夹层等因素,造成供给能力下降,后期产能一般会有较大幅度的衰减。为了分析总结出适用于本区块侏罗系增产改造的有力措施,对本区块2017年度侏罗系增产改造措施的内容及其效果进行了归纳总结,提出两大主要增产措施即原层补孔爆燃压裂和小砂量解堵压裂工艺的油井测井显示、油层射开程度、采出程度等方面的适用条件,为下一步侏罗系油藏措施方案提供必要的依据。实践表明,一是补孔爆燃压裂适用于Ⅰ类、Ⅱ类油层,射开程度低于1/3,含水为中低含水(<50%),液量低,采出程度较低(<3000t)的油井效果较好;二是小砂量解堵压裂工艺适用于Ⅰ类、Ⅱ类、Ⅲ类油层,射开程度低于1/3,采出程度较低(<3000t)的油井效果较好,措施增油效果好,对于采出程度>5000t的油井不适用。以上成果认识有利于进一步提高单井产量,对于吴起油田白河区块及其他与吴起油田相似的侏罗系油藏的开发具有重要意义。

Most of the Jurassic reservoirs in Baihe block of Wuqi oilfield are nose-like tectonic reservoirs with edge water development.The natural energy is relatively abundant,and the initial productivity generally can be higher.However,the heterogeneity of the oil layer is more prominent,with interlayer interlacing and other factors,resulting in decreased supply capacity,post-production capacity will generally have a more substantial decline.In order to analyze and summarize the effective measures for the stimulation of the Jurassic production increase in this block,summarize the 2017 Jurassic measures for increasing production and its effects in this block,and put forward two major stimulation measures,namely,well logging with well-fractured and small sand volumetric depressions and fracturing shows that the conditions of application,such as the degree of openness and degree of oil recovery,provide the necessary basis for the next step of the Jurassic reservoir measures.The practice showed that the first is that the deflagration of the fill hole is suitable for classⅠand classⅡreservoirs,the degree of opening is less than 1/3,the water cut is low and medium(<50%),the fluid volume is low and the degree of recovery is less than 3000 t oil well is better.Second,the amount of small sand volumetric solution and plugging fracturing technology is suitable for classⅠ,classⅡand classⅢreservoirs,with the opening degree being lower than 1/3 and the oil well with the lower degree of recovery<3000 t being better,measures to increase oil efficiency,for the production of more than 5000 t of wells do not apply.Recognition of the above results is conducive to further improve single-well production,which is of great significance for the development of Baihe block in Wuqi oilfield and other similar Jurassic reservoirs in Wuqi oilfield.