摘要
元坝地区钻井存在地质条件复杂、钻井难度大、不确定因素多等难点,井漏和溢流的频发层位集中在自流井组和上沙溪庙组。针对该地区前期井身结构存在表层套管和技术套管下深浅、裸眼段地层相互制约等问题,进行了超深井井身结构优化设计,优化了套管层次,选择了合理的必封点,增大了一开、二开和三开套管下深,增加了下部地层套管尺寸。优化后的井身结构不但能够有效封隔复杂层位,而且为空气钻井等新技术的应用和后期产层的高效开发创造了有利条件。现场应用表明,井漏由原来的平均每井4.4次减至1.9次,溢流由平均每井1.6次减至0.4次,空气钻井平均进尺增加51.26%,平均钻速提高64.3%。井身结构优化后,钻速提高,钻井周期缩短,满足了元坝地区超深井安全高效钻井的要求。
Yuanba Area with complex geological conditions faces many drilling difficulties and a num- ber of uncertain factors in which most circulation loss and overflow takes place in Ziliujing formation and upper Shaximiao formation. In view of problems such as shallow casing set depth and interaction in the open hole formation, etc. in previous drilling activities in this area, the casing program of deep wells was op- timized with improved casing structure, selection of seal points, deeper casing setpoint and larger casing size for the lower formation. This optimized well structure can not only isolate complex formations effectively, but also create favorable conditions for air drilling and application of other new techniques and efficient de- velopment in later time. Field application shows the probability of leakage for each well dropped from 4.4 to 1.9,overflow from 1.6 to 0.4, average air drill footage increased by 51.26 ~//0, and average drilling speed increased by 3.64~. The optimized well structure resulted in increased drilling speed and less drilling cy- cle,which met the requirements for safe and efficient drilling of Yuanba ultra-deep wells.
出处
《石油钻探技术》
CAS
CSCD
北大核心
2013年第4期83-86,共4页
Petroleum Drilling Techniques
基金
国家科技重大专项"大型油气田及煤层气开发"(编号:2011ZX05022)部分研究内容
关键词
超深井
井下故障
井身结构
元坝地区
ultra-deep well^downhole complexity~ casing program^Yuanba Area
