CHENG Yuanfang1, WU Lingyan1, CUI Qing2, XU Junliang2, DONG Bingxiang1
1. School of Petroleum Engineering, China University of Petroleum, Qingdao 266580, Shandong Province, China;2. Drilling Technology Research Institute, Shengli Petroleum Administration, Sinopec, Dongying 257017, Shandong Province, China
Abstract：Risk prediction and analysis is essential for risk control because of the uncertainty of coring project. Combined with the characteristics of coring project, the risk factors and events were recognized and analyzed effectively; the risk assessment system and mathematic model were established. Using Monte Carlo simulation method as well as AHP, the risk of coring project could be analyzed and calculated. With the consideration of various uncertainly risk factors, combination sampling method was applied to get a quantized risk probability distribution. Meanwhile, according to the simulation results, the risk index of each factor was available which quantized its corresponding contribution to the risk of the project. Then, the risk factors or events with high index could be found based on the analysis of probability, which is helpful in risk management of coring project and promoted the success ratio and recovered the rate of coring. This risk analysis method covered a variety of possibilities and delivered the uncertainties of parameters; its counting process reduced the loss of information, then the result is more accurate. Meanwhile, the sensitivity analysis could be carried on the base of data samples for deeper insight. On one hand, this study established a new evaluation methodology and supplied decision basis for the risk analysis and management of hydrate coring project; on the other hand, it made the foundational research work for subsequent more perfect hydrate coring project evaluation. Research showed that this method can achieve a good evaluation effectiveness and its prediction results are reasonable and practicable.