靖安油田张渠二区底水油藏堵水调剖工艺技术及应用

Water-plugging and Profile Control Technology and Its Application in Bottom Water Reservoir in Zhangqu2 Block of Jing ′an Oilfield

靖安油田张渠二区长2底水油藏经过20多年的开发,注入水沿砂体展布方向单向突进,大部分井已进入中高含水开发阶段,平面及剖面上的矛盾突出,开发效果变差。立足底水油藏地质规律及见水特征认识,在前期注水井堵水先导性试验基础上,进一步总结分析底水油藏弱凝胶堵剂体系调剖效果,针对单点调剖、大排量施工导致油井水线推进速度快致使油井含水上升过快、措施有效期短等突出矛盾,选择性地开展室内注入堵剂体系评价,优选沉淀型凝胶颗粒堵剂进行室内研究和矿场试验,采用连片、多段塞组合、连续交替注入工艺,并在施工过程中充分结合油井生产动态特征,在段塞设计和工艺参数上再次进行了优化,即增加二次封堵段塞、适当加大了无机堵剂用量和控制施工排量,能有效控制油井底水推近,提高水驱效率。通过近三年的矿场应用与适用性评价,形成了适合底水油藏特征的堵水调剖工艺技术,为保持区块的稳产起到了重要支撑作用。

The bottom water reservoirs in Zhangqu2 block of Jing＇an oilfield have been developed for more than 20 years.Water was injected along the direction of sand body distribution in one way,and most of the wells have entered into the development stage of medium-high water cut.Contradiction on plane and profile made the development effect poor.Based on the understanding of geological rule and water breakthrough char- acteristics in the bottom water reservoir, pilot test of water plugging in water injection well was done in early period ,and profile control result of weak gel system in the bottom water reservoir was analyzed.In the period of development ,great increase of water cut and short validity of the measures are obvious resulted from rapid flooding velocity for single-point profile control and large-displacement operation.Injected plugging agent sys- tem is evaluated in the laboratory and then precipitated gel particle plugging agent is optimized.The optimized agent is injected continuously and alternatively with multiple slug combination in the field.According to oil well performance,plug design and process parameters are optimized again,that is,secondary plugging slug is increased,inorganic plugging agent is applied with more dosage appropriately and construction displacement is controlled.Advance of the bottom water may be controlled effectively and water flooding efficiency may be enhanced.After field application and applicability assessment for three years,water plugging and profile control technology suitable for the bottom water reservoir characteristics is formed ,which plays an important support- ing role in maintaining the block production stable.