英买力气田群部分井出砂原因分析

REASON ANALYSIS ON SAND PRODUCTION IN SOME WELLS OF THE YENGIMAHALLA GAS FIELD CLUSTER

英买力凝析气田群地理位置位于新疆维吾尔自治区新和县与温宿县境内,构造位置处于库车前陆盆地前缘隆起带西端。该气田群包括英买7—19、羊塔1、玉东2、羊塔5等8个油气田,油气藏类型复杂,除羊塔5为挥发性油藏外,其余均为凝析气藏。根据组合模量法计算,该气田群内所有区块均不应出砂,然而测试及生产中却发现部分井存在出砂的情况。为此,对该气田群部分井出砂原因进行了分析,结果认为:英买力气田储层物性好,孔隙度大,岩石胶结不致密,老井地层在完井液长期浸泡后会对近井地层的岩石胶结物造成一定程度的破坏,从而造成地层出砂,但这种出砂与岩石骨架出砂有着本质的区别,只是发生在近井地层的小范围之内,不会造成大面积出砂,更不会引起地层垮塌堵塞井筒或影响产能。通过现场放大生产压差试验,证实了上述结论的可靠性。

The Yengimahalla condensate field cluster is located geographically in Xinhe and Wensu counties of Xinjiang Uygur Autonomous Region and structurally at the western end of the frontal uplift zone of Kuqa foreland basin.The gas field cluster consists of 8 fields including Yengima 7-19,Yangta-1,Yudong-2 and Yangta-5,all of which are gas condensate reservoirs,except for Yangta-5 which is a volatile oil reservoir.Combined modulus calculation shows that no sand production is expected in all the blocks of the field cluster.However,sand is produced in some wells during test and production.An analysis of the causes of sand production gives out the following understandings.The reservoirs are characterized by good physical properties,large porosity and poor cementation.The cements in the near wellbore formations may be damaged to some degree due to the long immersion in completion fluids,resulting in the false image of sand production.However,this kind of sand production is fundamentally different with rock frame sand production in that it occurs only in the near wellbore formations,and cannot result in large scale sand production,formation caving or reduction of deliverability.Field experiment through increasing producing pressure drop verifies that the above conclusions are reliable.