膨胀悬挂直连型尾管小井眼二开次钻完井技术

Expandable Liner Hanger and Extreme Line Casing for the Second Spud Slim Hole Drilling and Completion

φ177.8 mm套管内的小井眼窄间隙井钻遇高压层、易坍塌地层及漏失地层时,若采用常规技术手段和井身结构则难以下入技术套管封隔漏失层实施二开次钻井及完井作业,若采用膨胀套管充当技术套管,构建"临时井壁"封隔复杂层将面临成本高、周期长等问题。为此,提出了悬挂直连型尾管代替膨胀套管的封隔方案,利用膨胀悬挂器悬挂大直径尾管和提供尾管头密封的优势封堵复杂层,然后下入随钻扩眼钻头钻至目的层,实现二开次完井。对随钻扩眼钻头和大通径膨胀悬挂器进行了设计,对尾管尺寸进行了优选,对固井附件和固井工艺进行了设计和优化。3口井的试验结果表明,该技术实现了二开次套管完井作业,能成功封隔漏失层,满足钻井及完井要求。

When drilling a slimhole into high pressure, easy to collapse and loss formation from φ177.8 mm casing well, the intermediate casing will be difficult to run in hole to isolate the thief zone and conduct the second spud drilling and completion by using the conventional techniques and wellbore configuration. While the ＂temporary wall＂ built by the expandable casing would lead to issues like high cost and long operation time. Thus, the extreme line liner banged by expandable liner hanger is proposed as an alternative for the expandable casing. The expandable liner hanger hangs the large diameter liner and provides seal at the liner head to isolate the complex layer. Then, the reaming while drilling bit is run to drill down to the target layer to complete the second spud. The reaming while drill- ing bit and the large diameter expandable hanger are designed. The size of the liner is selected. The cementing acces- sories and cementing techniques are designed and optimized. The test results in three wells indicate that the devel- oped technology could achieve the second spud casing completion to isolate the thief zone, thus meeting the re- quirements of drilling and completion as well as providing techniques for the slimhole drilling and completion.