页岩气暂堵压裂技术在威远龙马溪组的应用

Application of Temporary Plugging Fracturing to Shale Gas in Longmaxi Formation, Weiyuan Block, Sichuan Basin

四川盆地海相地层威远区块页岩气资源丰富,储层非均质性强,很难设计与储层精确地质模型相匹配的压裂裂缝模型,使得裂缝控制技术实施难度很大。暂堵压裂技术能根据储层特点自动选择甜点,充分改造低效储层,使井筒覆盖和油气藏接触最大化,提高采收率。通过暂堵剂优选和评价,根据暂堵技术及工艺原理,结合威远区块龙马溪组储层特征,形成了适合威远区块的暂堵体积压裂工艺,现场试验显示WY23-1HF等5口井初期产量较高,为四川威远页岩气的高效开发提供了技术保障。

In Weiyuan block, Sichuan Basin, there are abundant shale-gas resources from marine reservoirs. However, due to these strong heterogeneous reservoirs, it's hard to develop a fracturinginduced fracture model to match with another fine geological reservoir model, resulting in great difficulty in fracture control. Temporary plugging fracturing is just one technology to automatically choose a sweetpoint according to reservoir characteristics, to fully reconstruct those reservoirs with low efficiency, to get the most out of the contact between wellhead coverage and reservoir, and to enhance recovery. Moreover, after an optimization and evaluation of temporary plugging agent, based on the plugging technology, we developed a temporary plugging volumetric fracturing available for Longmaxi Formation in this block. Its application to five wells including WY23-1 HF shows that, compared to those wells adopting conventional fracturing, the five wells by temporary plugging volumetric fracturing have higher testing production and longer period of stable output. Generally, this fracturing provides powerful technological support for developing shale gas of Weiyuan block with high efficiency.