Oil ＆ Gas Drilling Risk Analysis Utilizing Quantitative Risk Assessment

• Published in: 淡江理工學刊 Vol. 21; no. 4; pp. 541 - 546
• Main Authors: Zhichuan Guan, Ya-Nan Sheng, Chuan-Ming Xi, Ming Luo, Wentuo Li
• Format: Journal Article
• Language: English
• Published: 淡江大學 01.01.2018
• Subjects: QRA; Monte-Carlo Method; Formation Pressure with Confidence; Drilling Risk
• ISSN: 2708-9967
• DOI: 10.6180/jase.201812_21(4).0005

Oil and gas drilling engineering has the characteristics of high investment and high risk, especially when drilling in the deep and complex or offshore formation. Through the investigation of the existing drilling risk assessment methods, we found that the traditional methods often neglected the mechanism of drilling risk. These methods only transplant the risk assessment methods, which is commonly used in other engineering areas to the drilling engineering. We can only get the results of qualitative or semi-quantitative risk assessment. The existing methods cannot guarantee the safety of high risk drilling. Therefore, it is necessary to establish the quantitative drilling risk assessment method. Firstly, the uncertainty of the formation pressure was analyzed and the probability distribution of formation pressure was obtained by using the Monte-Carlo method. Then according to the pressure constraint criterion, we established the safe window of drilling fluid density with confidence. Based on that, through the risk mechanism analysis and based on quantitative risk assessment method (QRA), the quantitative analysis method for oil and gas drilling risk was established. The risk profile of the whole well section can be gotten. Through case studies, this method can be used to predict the probability of drilling risk, and the prediction results were in good agreement with the actual drilling risk.