<p><em>With the increase of development the well integ</em><em>c</em><em>rity</em><em> </em><em>problem are becoming more and more serious. This article uses the </em><em>F</em><em>ault </em><em>T</em><em>ree </em><em>A</em><em>nalysis (FTA) method for many factors, such as completion, production and operation process, pressure annulus, the cementing quality, the wellhead system and leakage of pipe string.</em><em> </em><em>Many wellbore risk factors to conduct a comprehensive analysis and evaluation. Through the qualitative analysis of wellbore integrity failure risk, determining the level of risk factors and establishing the damage analysis model of the wellbore. According to the selected blocks in Shengli Oilfield example analysis of single wells find out the minimum cut sets, the minimum path sets and structure importance. The results showed that the selected block probability of top event is calculated and it’s 0.9961, and the actual selection conforms to statistics prove that the proposed based on the FTA wellbore damage risk analysis method is feasible, and through quantitative analysis and calculation of basic events of different important degree of parameters.</em></p><p><em>According to these risk factors for prevention of failure risk control measures are put forward, which provides reference for predict wellbore integrity to ensure the safety of oil and gas production run smoothly.</em></p>
Investigating Risk Factors in Tender Process Effecting on Contract Implementation Stage in Onshore Oil and Gas Production Facilities Projects