稠油油藏黏土矿物特征及敏感性损害研究

CHARACTERISTICS AND SENSITIVITY DAMAGE OF CLAY MINERALS IN HEAVY OIL RESERVOIR

稠油油藏资源量巨大,但其高孔、高渗、黏土矿物发育的地质特征,使得储层在钻井过程中极易遭受工作液滤失而带来各种严重的储层伤害问题。认清储层敏感性矿物类型和潜在损害特征是保护稠油油藏的基础。通过分析得知,该储层具有黏土矿物含量高及类型丰富的特征。在室内进行的敏感性损害评价实验结果表明,储层具有弱-中偏弱的速敏和强的水敏,毛细管自吸实验结果表明,储层具有较强的吸水趋势,应防止钻井过程中因毛细管自吸带来的水相圈闭损害。该研究为钻井过程中因毛细管自吸带来的水相圈闭损害的评价提供了依据。

The heavy oil reservoirs have the characters of high porosity and high permeability,the serious formation damage will be caused by the drilling fluids loss during the drilling. In order to pro-tect heavy oil reservoir,the sensitivity clay types and formation dam-age features were analyzed. The analytic result showed that the heavy oil reservoir had rich clay minerals and content was high. The sensi-tivity damage experiment indicated the reservoir had strong water sensitivity,its water-absorbing capacity was very high by capillary. So,the aqueous trap damage caused by capillary imbibition should be prevented during drilling.