Method and device for predicting layered gas production capacity of coalbed methane production well

Abstract

The application discloses a method and a device for predicting the layered gas production capacity of a coalbed methane combined production well, belonging to the technical field of coalbed methane development and drainage. The technical solutions provided in the embodiments of the present application can determine the gas production capacity of each layer based on the actual production parameters of each well before the gas production of the coalbed methane well, and provide a basis for the formulation of drainage and production systems such as the stable gas production volume and stable production pressure of the coalbed methane well, and Because its gas production capacity is judged according to the actual production parameters of each well, it can effectively avoid the adverse effect of the heterogeneity of the coal seam plane on the prediction results, and greatly improve the prediction accuracy, and the above prediction process does not require a large number of geological parameters and Advanced geological knowledge, simple operation, simple method, low requirements on user ability, suitable for large-scale promotion on site, and can be popularized and applied to all coalbed methane wells with two or more layers commingled.

Description

technical field [0001] The application relates to the technical field of coalbed methane development and drainage, and in particular to a method and device for predicting the gas production capacity of layers of a coalbed methane production well. Background technique [0002] The main CBM reservoirs in the south of Qinshui Basin are 3 # Seam and 15 # Coal seams, in order to increase single well production and reduce development costs, generally use single well drilling to penetrate 15 # seam, using 3 # Seam and 15 # The coal seam is developed in the way of partial pressure and joint mining. Due to the strong plane heterogeneity of coal reservoirs, the production contribution of the lower layer or the upper layer may be extremely low in double-layer combined production wells. However, since the two layers are exploited at the same time, the production is combined into one, so it is impossible to judge the gas production capacity of each layer . Judging the gas productio...

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Problems solved by technology

[0004] However, the production observation method and the analogy method can only judge the gas production capacity of layers after gas production or even after reaching a stable gas production rate. After gas production, the drainage and production control of CBM wells enters the middle and late stages, which cannot effectively guide the drainage and production management of CBM wells.

However, predicting gas production capacity through geological parameters requires many geological parameters. Each well is tested for geological parameters, which takes a long time and costs a lot, and is not suitable for large-scale application on site.

At present, most of the three methods are indirect speculation based on experience, and the plane heterogeneity of coalbed methane reservoirs is strong, and the difference between wells is large. Therefore, the accuracy and reliability of the three methods are relatively poor, and they cannot adapt to the one well one method. Mining Control Requirements

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