N80-1油管在水力壓裂作業(yè)過程中開裂原因分析

Analysis on Causes for N80-1 Tubing Fracture during Hydraulic Fracturing Operation

摘要: 采用斷口宏觀分析、斷口微觀分析、金相檢驗等方法，對N80-1油管在進行油層水力壓裂作業(yè)過程中發(fā)生脆性開裂的原因進行分析。結(jié)果表明：內(nèi)壁存在一條深0.2耀0.8 mm的芯棒劃傷是導致N80-1油管在壓裂過程中發(fā)生開裂的主要原因；N80-1油管的沖擊韌性較低也致使該油管發(fā)生脆性開裂。改選用沖擊韌性值高的油管進行壓裂作業(yè)將會降低壓裂過程中油管發(fā)生脆性開裂的概率。

Abstract: Causes for brittle fracture of the N80-1 tubing as occurring during hydraulic fracturing operation at oil reservoir are investigated by means of both macro and micro analyses on the fracture，and metallographic test，etc. The results indicate that the primary cause for the said fracture of the tubing is a 0.2~0.8 mm-deep scratch as made by the mandrel on the inner surface thereof. In addition， rather low impact toughness of the N80-1 tubing is also responsible for the brittle fracture. Accordingly，using the tubing with high impact toughness for hydraulic fracturing service will reduce the probability of brittle fracture.