A method for identifying shale gas reservoirs while drilling using discriminant analysis

Abstract

The invention discloses a method for identifying a shale gas reservoir while drilling by utilizing a discriminant analysis method. The method comprises the following steps that (a) drilled shale gas horizontal well data in the same block are integrated and classified; (b) data analysis is performed on the classified region data, effective shale gas reservoir discriminant parameters are preferably selected, and discriminant factors are established; (c) a discriminant function which can effectively identify the shale gas reservoir is established by utilizing the disriminant factors; (d) according to the established discriminant function, interpretation while drilling is performed on the shale gas reservoir. According to well logging interpretation and oil production testing data of a drilled shale gas horizontal well, the discriminant factors established through optimized while-drilling parameters are utilized, and the discriminant function which can effectively identify the shale gas reservoir is established through discriminant analysis. In this way, while-drilling identification on the shale gas reservoir is achieved, and the problem that a while-drilling interpretation method of a shale gas reservoir has defects is solved.

Description

technical field [0001] The invention relates to a method for identifying shale gas reservoirs while drilling by using a discriminant analysis method, belonging to the field of oil and gas exploration and development. Background technique [0002] Shale gas is natural gas stored in shale in free and adsorbed states. It is gradually becoming a hot spot in oil and gas exploration. Domestic shale gas horizontal well development is about to be carried out on a large scale. For the interpretation method of shale gas while drilling, for example, the study on the logging response characteristics and identification methods of shale gas reservoirs disclosed in the 18th issue of "Science and Technology Herald" in 2012. [0003] However, due to the particularity of shale gas reservoirs, in addition to the comprehensive logging parameters, there is only one logging-while-drilling parameter of gamma while drilling, and there are few parameters while drilling. Moreover, the current level ...

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Problems solved by technology

According to the well logging interpretation and oil testing data of drilled shale gas horizontal wells, the present invention utilizes the discriminant factor established by the optimal parameters while drilling, and establishes a discriminant function that can effectively identify shale gas reservoirs through discriminant analysis, so as to realize the identification of shale gas reservoirs. The identification while drilling of shale gas reservoirs solves the problem of lack of interpretation methods while drilling shale gas reservoirs

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