頁巖氣井套管損壞原因分析及認識

Analysis and Understanding of Casing Damage in Shale Gas Well

摘要: 統(tǒng)計國內(nèi)頁巖氣開采中發(fā)生的套管損壞的相關(guān)數(shù)據(jù)，并結(jié)合現(xiàn)有井況環(huán)境，總結(jié)引起套管發(fā)生點變形的根本原因。分析認為：由于套管管體受到的外界非均勻載荷超出套管能力極限，從而導致套管整體結(jié)構(gòu)失穩(wěn)，發(fā)生點變形。采用有限元方法計算套管能承受的非均勻載荷，并通過實物評價試驗進行驗證，為頁巖氣用套管選型提供理論依據(jù)。提出幾種減少頁巖氣井套管損壞變形的解決方案。

Abstract: Analyzed in the paper are the relevant data of casing damages occurred in domestic shale gas exploiting operations as well as the exsisting shale gas well conditions to find out the fundamental causes for point deformations appeared on casings.The analysis indicates that when the external non-uniform load borne by a casing body exceeds its limit,it will lead to overall structure instability of the casing and cause point deformation.The bearable non-uniform load for a casing is calculated by finite element method and verified by actual product evaluation test to provide a precise theoretical basis for the type selection of casings for shale gas well.Some solutions for reducing casing damages in shale gas wells are put forward.