决定砂岩油藏酸化效果因素研究——以准噶尔盆地东部火烧山油田为例

Study on the Decision Factors in Effectiveness of Acidizing Stimalation in Sandstone Reservoir——An example of HuoShaoShang Oilfield in Eastern Junggar

砂岩油藏酸化增产技术在全国油田开展的较早 ,取得了一定的效果 ,但是多数油田增产幅度小。火烧山油田从开发初期就进行了酸化增产实验 ,酸化效果明显好于其它油田 ,分析原因主要有 :火烧山油田储层以钙质胶结为主 ,泥质含量低有利于酸化作业 ;储层发育隐裂缝沟通了远井地带 ,只要近井地带渗透率增加便可以增加供液能力 ;被方解石充填的充填缝被溶解后可达到后期造缝目的 ,渗透率呈数量级提高 ;储层堵水污染后 ,近井地带用氧化酸处理后可增加供液能力又可以启动新层 ;乳化酸和缓速酸体系的应用增加了酸化处理半径 。

Acidizing stimulation in sandstone reservoir begins early in all oilfields in China and the better effectiveness has been achieved. But in most oilfields there is less stimulation magnitude. At the beginning of the development in HuoShaoShang oilfield, acidizing stimulation has been used to improve recovery and the better effectiveness has been achieved compared with other oilfields. The main reasons are : Firstly, the reservoir in HuoShaoShang oilfield is mainly calcite cement and low shale index, which are good for acidizing treatment. Secondly, cryptic fractures developed in reservoir connect with far well region, so the fluid supply capacity will increase so long as the rate of permeability of the region around well increases. Thirdly, the packing fractures filled by calcite, after melting, will generate width fractures. So the rate ofpermeability increases on a numerical scale.Fourthly, after water plugging, the region near well, after being treated by oxide acid, has high fluid supply and new layers are developed. Finally, the application of emulsified acid and retarded acid system make the acid treatment radius increase. All these make the acidizing stimulation in HuoShaoShang get a good effect.