南堡油田1号构造东一段储层酸敏分析

酸化也会产生某些不溶性物质堵塞孔喉,给储层带来新的损害,即产生酸敏反应。储层酸敏性分析可为储层酸化改造及酸液配方研究提供依据。南堡油田1号构造东一段34块岩心酸敏评价结果表明储层土酸酸敏程度为强—极强。酸敏流动评价实验结果与所用岩心的渗透率、黏土总含量、不同黏土矿物含量,测试流体的酸浓度等有关。渗透率高的岩心易发生酸敏损害,黏土含量高的岩心酸敏损害原因复杂。测试流体中HF酸浓度越高,酸敏损害程度越大。高浓度酸液对胶结物的过度溶失,破坏岩石结构,产生微粒,堵塞孔喉,造成渗透率的降低,是造成南堡油田1号构造东一段酸敏强的主要原因。酸敏地层采用合适的酸液浓度或体系,可以采取酸化达到增产目的。

The analysis of acid sensitivity on the first east section of No.1 structure in Nanpu Oilfield

Acidification will produce some insoluble materials which will plug the pore throats and bring new damage on oil reservoirs.This phenomenon is called acid-sensitivity.In order to provide materials for acidizing fluid and acidification,the acid-sensitive analysis is conducted.It is experimented that the mud acid sensitivity is strong or too strong in the east section of No.1 structure of Nanpu Oilfield in the way of 34 drill cores.This result is related to the permeability,the total content of clay,the content of different clay mineral and acid concentration.it is easy to cause acid-sensitive damage in high permeability zones.There are many factors which will influence the acid-sensitive formation damage in the high mineral cores.The higher the concentration of HF acid is,the greater the acid-sensitive formation damage is.The main reasons for strong acid sensitivity in the east section of No.1 structure of Nanpu Oilfield is that the overdissoluted cements,which have caused the breaking structure of rock,the migration of particles blocked seepage pore and decreasing permeability.It is very important to use proper acid systems and proper concentration to increase production in the acid-sensitive reservoirs.