鄂尔多斯盆地子洲—清涧地区上二叠统储层损害因素分析

FORMATION DAMAGE ANALYSIS OF UPPER PERMIAN IN ZIZHOU-QINGJIAN AREA,ORDOS BASIN

鄂尔多斯盆地子洲-清涧地区上二叠统气藏具有常温低压低孔低渗的特点。研究表明,储层应力敏感性和水锁效应强,是储层伤害的主要形式,其原因是由于储层平均孔喉半径细小,微裂缝较发育,喉道类型以片状喉道为主造成的。储层速敏性、水敏性、盐敏性、碱敏性总体表现为弱敏感性,仅部分岩样反映出较强的敏感性,这与岩样中粘土矿物类型不同紧密相关。表现强敏感性的岩样,一般含有较高的伊利石或绿泥石,而高岭石含量较高的岩样,敏感性较小。

The Upper Permian gas reservoir in Zizhou-Qingjian area, Ordos Basin is characterized by normal temperature, low pressure, low porosity and low permeability. As indicated by study, the formation damage is mainly caused by the strong stress sensitivity and water lock effect. In the reservoir with sheet throat as the soul, the average radius of pore throat is very thin and the microfractures are very developed. These two become the forms of formation damage. Most rocks samples indicate weak sensitivities, such as velocity, water, brine and alkali sensitivity, but only a few of rock samples show strong sensitivity. Different clay minerals in sample rocks have different sensitivities. Rocks with high illite or chlorite have more strong sensitivities than those with high kaolinite.