保护安棚地区裂缝孔隙型储层的钻井完井液

Drill in fluid for fissure-pore formation protection in Anpeng oilfield

针对河南油田安棚深层系低孔、低渗的特点,在调查安棚深层系储层保护现状的基础上,开展了储层特征及潜在损害因素分析、储层损害机理分析,评价了常用钻井液处理剂与地层水的配伍性、抑制性、在15％HCl溶液中的溶解率和生物毒性以及钻井液损害储层的程度,配制出了保护安棚地区裂缝孔隙型储层的钻井完井液。该体系所用处理剂与地层水相配伍,不产生沉淀,酸溶率高,无生物毒性,对环境不会造成污染,而且由于在现有钻井液中加入了2％～3％QS-1和1％～2％JDB,降低了对储层的损害,使渗透率恢复值达到80％,该钻井液现场施工简单,维护容易。

Deep layers in Anpeng oilfield of Henan oilfield has characteristics of low porosity and low permeability. Based on investigating of the present formation protection situation, reservoir characteristic, potential damage factors and damaging mechanism were investigated; meanwhile the compatibilities between additives of conventional drilling fluids with formation water, their inhabitation, their solubility in 15% HC1 solution, biotoxicity and damaging degree to formation were also evaluated. A fluid system was worked out based on the study to protect fissure-pore formation of Anpeng oilfield. Additives used in this system are compatible with formation water, with no setting, and solubility in acid is high. With no biotoxicity, this fluid produces no pollution to the environment. Also, for 2%-3% QS-2 and 1%-2% JOB are added into the fluid system, damage to formation is reduced and the permeability recovery reaches 80%. Operation and maintenance in the field is simple and easy.