Study and application of a new method for predicting the production of low rank CBM wells
Abstract
Due to many factors affecting the production of low rank coalbed methane (CBM), it is difficult to predict the productivity. The difference of production ramp-up period is large, the fitting of peak production and peak date is difficult, and the efficiency of existing production prediction methods is limited. Based on the characteristics of typical curves of CBM, a new method is established in this paper. Based on the previous accurate history match of reservoir simulation and analysis of the characteristics of typical curves of production index, water gas ratio, pressure and cumulative water production of typical wells, a rate-cumulative water-method (RCM) mathematical model is established by using non-linear fitting method. The mathematical model is determined by historical fitting. The model parameters can predict the output of CBM quickly and accurately, and provide the production prediction data for the scheme formulation and field decision-making. Compared with other prediction methods, RCM improves the history fitting through correlation analysis, improves the reliability of prediction results. It can predict gas well production in both production ramp-up and declining periods. It does not need to update the reservoir model and is less time-consuming. So it is particularly suitable for predicting the production for a large number of wells in a short time. By comparing the production history of CBM wells in “A” block, the accuracy of RCM prediction result is verified.
- Publication:
-
Journal of Physics Conference Series
- Pub Date:
- August 2020
- DOI:
- 10.1088/1742-6596/1592/1/012057
- Bibcode:
- 2020JPhCS1592a2057L