基于地层因素的钻井井控风险定量评价方法研究

发布时间：2019-06-02 13:12

【摘要】：井喷及井喷失控是钻井工程中的头等灾难性事故,导致井喷事故的原因分为人为因素、钻井条件因素和地层等因素。从统计数据中发现地层因素所占的比例很大,甚至高达50%,所以说地层因素是导致钻井井喷的内在客观因素,因此做好基于地层因素的井控风险评估工作是有效防范井喷事故发生、减少事故损失的基础工作。在调研、统计的基础上总结了常用的风险的评价方法,并从评价方法的优缺点和适用性进行了分析比较。分析了灰色关联评价法用于钻井井控风险评价的优势,将其引入钻井井控风险评价。在应用中针对传统灰色关联评价方法的不足,借鉴TOPSIS法的原理进行相应的改进,使其更加适合单井井控风险进行定量评价。权重的计算是风险定量评价的核心技术之一,本文对比分析了常用的主观和客观权重确定法的原理、适用性及优缺点,并利用实例数据进行指标权重计算分析,结果表明单一采用主观或者客观权重确定法是有缺陷的。本文结合主、客观权重确定法优点,提出了主客观组合权重确定法,并说明其适用条件及具体计算步骤。从导致井喷的三个内在条件分析出发,结合现场实际建立了包含三个层次、12个指标的井控风险地层因素层次结构图,将每个指标划分为四个风险等级,建立了相应的等级标准。结合地层因素指标体系,以改进的灰色关联评价法为基础建立了基于地层因素的钻井井控风险评价模型。运用基于地层因素的钻井井控风险评价模型对3口典型的井进行了评价,确定其风险等级,由权重找到关键诱因,该风险等级和关键诱因与现场实际基本一致,验证了所建立的定量评价模型具有一定的可靠性。可以为现场工程技术人员识别钻井井控风险,特别是随钻井控风险,采取科学的工艺技术措施提供有意义的指导。
[Abstract]:Blowout and blowout out of control are the first catastrophic accidents in drilling engineering. The causes of blowout accidents are divided into human factors, drilling conditions factors and formation factors. It is found from the statistical data that the proportion of formation factors is very large, or even as high as 50%, so the formation factors are the internal objective factors that lead to drilling blowout. Therefore, doing a good job of well control risk assessment based on formation factors is the basic work to effectively prevent blowout accidents and reduce accident losses. On the basis of investigation and statistics, the common risk evaluation methods are summarized, and the advantages, disadvantages and applicability of the evaluation methods are analyzed and compared. The advantages of grey relational evaluation method in drilling well control risk assessment are analyzed and introduced into drilling well control risk assessment. In view of the shortcomings of the traditional grey relational evaluation method, the principle of TOPSIS method is used for reference to improve it, so that it is more suitable for quantitative evaluation of single well control risk. Weight calculation is one of the core techniques of risk quantitative evaluation. This paper compares and analyzes the principle, applicability, advantages and disadvantages of the commonly used subjective and objective weight determination methods, and uses the example data to calculate and analyze the index weight. The results show that it is defective to use the subjective or objective weight determination method alone. Based on the advantages of subjective and objective weight determination method, this paper puts forward the subjective and objective combination weight determination method, and explains its applicable conditions and concrete calculation steps. Based on the analysis of the three internal conditions leading to blowout, the hierarchical structure diagram of well control risk formation factors with three levels and 12 indexes is established in combination with the field practice, and each index is divided into four risk grades. The corresponding grade standards are established. Combined with the index system of formation factors, a drilling well control risk assessment model based on formation factors is established on the basis of the improved grey relational evaluation method. The risk evaluation model of drilling well control based on formation factors is used to evaluate three typical wells, and the risk grade is determined, and the key inducement is found by weight. The risk grade and key inducement are basically consistent with the actual situation in the field. It is verified that the established quantitative evaluation model has certain reliability. It can provide meaningful guidance for field engineers to identify the risk of drilling well control, especially the risk of well control while drilling, and to take scientific and technical measures.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE28

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