伊拉克Ahdeb油田储层损害机理研究

Reservoir damage mechanism of Iraq Ahdeb Oilfield

伊拉克Ahdeb油田储层属中—高孔低渗孔隙型碳酸盐岩油藏,测试的表皮因数平均高达6.21,属严重污染。由于其岩性、物性、孔隙结构和敏感性矿物特征与国内灰岩储层有较大的差异,所以其损害机理也不尽相同,为此开展了储层敏感性实验评价。研究结果表明,伊拉克Ahdeb油田的主要损害机理为水敏、盐敏、应力敏感性损害、水锁以及漏失引起的固相损害。提出了应注重强化钻井液对井壁的封堵性,尽量降低钻井液滤失量,选用可酸溶油溶的随钻堵漏材料等储层保护措施。

Iraq Ahdeb Oilifeld is medium-high porosity and low permeability carbonate reservoir. The average of skin factor tested up to 6.21 shows that it is heavily polluted. Iraq Ahdeb Oilifeld is quite different from domestic limestone reservoir due to the lithology, physical properties, pore structure and mineral sensitivity characteristics, so the damage mechanisms are not the same. For this, the res-ervoir sensitivity was experimentally evaluated. The experimental results showed that the main damage mechanism is water sensitivity damage, salt sensitivity damage, stress sensitivity damage, water blocking and solid damage resulting from lost circulation. Reservoir protection measures are put forward, such as strengthening the sealing of drilling lfuid for wellbore, minimizing the lfuid loss and select-ing acid-soluble or oil-soluble loss circulation material, which have achieved good sealing and reservoir protection effect.