浅层“次生高压气藏”安全钻井技术探讨  

Safe drilling technology used in shallow secondary high-pressure gas reservoirs at the Right Bank of the Amu Darya River

作　　者：刘廷富 吴先忠[1] 李万军[2] 胡超[3] 程旭 周海秋[2] 贺明敏[4] 

机构地区：[1]中国石油(土库曼斯坦)阿姆河天然气公司 [2]中国石油天然气集团公司钻井工程技术研究院 [3]川庆钻探工程有限公司钻采工程技术研究院 [4]西南石油大学石油工程学院

出　　处：《天然气工业》2011年第2期70-73,128,共4页Natural Gas Industry

基　　金：国家科技示范工程(编号:2011ZX-05059-002)

摘　　要：通常意义上的次生气藏是由于构造演化过程中,古气藏遭到破坏,引起天然气的再次转移和再分配而形成的气藏。而本文所指的"次生高压气藏"是指原本储集于深部地层中的天然气经人为建立的通道运移到浅部地层,在浅部具有储藏条件的地层里大量重新聚集所形成的气藏。土库曼斯坦阿姆河右岸探区皮尔古伊构造浅层高压气藏就是这种典型的"次生高压气藏",与地质意义上的次生气藏相比,存在着运移通道、与气源沟通状态、储层稳定性等方面的区别。该"次生高压气藏"的埋深浅、压力高,钻井液安全密度窗口窄,气体中含硫化氢,固井易漏、易窜,给钻井和固井施工都带来了困难和风险。为此,探讨并提出了以下有针对性的安全措施:对着火井井口安装引流罩可控放喷点火、在着火井边缘钻生产井强采泄压、钻定向救援井挤注水泥封堵老井井筒原生气体运移通道,由此集成了一套"次生高压气藏"安全钻井与治理的技术思路和实施方案。采用该套技术方案有可能排除皮尔古伊构造浅层"次生高压气藏"给钻井作业带来的风险,并减轻着火井放喷燃烧对气田产能的破坏。A secondary gas reservoir is normally formed due to secondary natural gas migration and distribution after the ancient gas reservoir being damaged during the evolution of geological structures.While the secondary high-pressure gas reservoir so called in this paper is a shallow gas reservoir formed by natural gas migrating from the deeper formations through the artificial channels up into the shallow reservoir formations.The Pirgyi gas pools at the Right Bank of the Amu Darya River in Turkmenistan are just such typical secondary high-pressure gas reservoirs.Compared with those in the geological meaning,there exists difference in migration channels,communication with gas source,and the reservoir stability.The secondary high-pressure gas pools in Turkmenistan have shallow burial depth,high pressure,narrow drilling fluid window,H2S content,and frequent occurrence of lost circulation and gas channeling,all of which will pose threats to drilling and cementing.The following corresponding technical measures are proposed herein for those challenges: a gas stream-guiding barrel placed over the burning wellhead to put both blowing out and gas ignition under control;a pressure relief well drilled near a firing well,a directional relief well drilled to squeeze cement to plug the migration channel of the original natural gas in the wellbore of a mature well,etc..Thus,a set of safe drilling and rehabilitation program and technology is formed for the secondary high-pressure gas pools.The drilling threats at the Pirgyi structure can hereby be eliminated and the damage can also be reduced to the production potential of the gas field caused by the gas burning at the accident well.

关 键 词：土库曼斯坦阿姆河右岸 皮尔古伊构造 浅层次生高压气藏 安全钻井技术 井喷 硫化氢 灭火 救援 

分 类 号：TE24[石油与天然气工程—油气井工程]