Method for quantitative evaluation of geological risk of oil gas drilling target

Abstract

The invention provides a method for quantitative evaluation of geological risk of an oil gas drilling target. The method comprises the following steps: determining an establishing principle of a geological risk assignment standard, determining geological risk factors, determining a main control factor and a correction factor in each geological risk factor, creating a geological risk factor assignment standard, assigning a geological risk factor of the oil gas drilling target, calculating the evaluation values of respective geological risk factors, and calculating the probability of oil and gas accumulation of the oil gas drilling target. The method for quantitative evaluation of geological risk of the oil gas drilling target establishes a geological risk evaluation program and standard of the oil and gas drilling target, achieves quantitative evaluation of geologic risks before drilling the oil gas drilling target, and improves a pre-drilling risk evaluation ability and the success rate of oil and gas exploration.

Description

technical field [0001] The invention relates to a quantitative evaluation method for geological risk, in particular to a quantitative evaluation method for geological risk of an oil and gas drilling target. Background technique [0002] The concept of risk was first proposed in the field of economics at the end of the 19th century, and has been widely used in various disciplines and fields. Risk assessment is based on the identification of risk factors, estimating the nature of risk, estimating the probability of occurrence of risk events, evaluating the consequences of risk events, and determining the order of their severity. [0003] Oil and gas exploration and development is a high-input, high-risk industry. Since the 1980s, the general concepts and methods of geological risk analysis were introduced into China. With the launch of the second oil and gas resource evaluation in the early 1990s, the risk probability method was initially formed. . At the end of the 1990s, m...

AI Technical Summary

Problems solved by technology

For example, the article "Geological Risk Assessment of Dabancheng Sub-sag Trap" published in "Xinjiang Petroleum and Natural Gas" in Volume 3, Issue 3, 2007, proposed a geological risk assessment method, which includes reliability, trap conditions, reservoir However, this method has the following problems: source rock is the material basis for hydrocarbon accumulation, and this method does not consider source rock Factors; in oil and gas exploration, the reliability of the description results of each geological factor is obviously different with the different prediction methods and verification methods, but in this method, the confidence of the data is only described in the factor of reliability, while in the reservoir The confidence level of the data is not considered in the three factors of strata, cap rock, and migration-accumulation supporting conditions; it is obviously unreasonable to define the risk level of geological factors based on the size of the parameters such as reservoir thickness, cap rock thickness, and trap area. For example, as long as the cap rock reaches a certain thickness, it can play the role of sealing oil and gas, so cap rocks with a thickness greater than this should be considered as equivalent.

Images