Production Forecasting Methods for Single Wells and Entire Area of Shallow Shale Gas in the Haiba Block, Zhaotong Demonstration Area

Abstract The shallow shale gas in the Haiba block of the Zhaotong Demonstration Area is characterized by shallow burial depth, low formation pressure, and high adsorbed gas content. The production capacity of individual wells within the block varies significantly, with strong heterogeneity and complex influencing factors. Currently, there is no targeted method for single-well or full-area production capacity prediction. To address these issues and characteristics, this study utilized actual production data from 84 wells in the Haiba block. For single-well scale analysis, a new production prediction model was developed based on the traditional transient hyperbolic decline model, incorporating the effects of shallow shale gas desorption as derived from adsorption-desorption experiments. The new decline model enables more accurate production capacity predictions for the saturated adsorption zone, transition zone, and unsaturated adsorption zone of shallow shale gas in Haiba. For the full-area scale, using a three-dimensional geological model and geomechanical model, the normalized production of the best 12 months was selected as an indicator. A multifaceted single-factor analysis of the main production-controlling factors was conducted to examine the relationships among reservoir quality, completion quality, engineering quality, and production capacity indicators for each well. Data mining results show that production capacity is primarily influenced by five parameters: TOC (total organic carbon), adsorbed gas proportion, pore pressure coefficient, proppant intensity, and cluster spacing. A five-parameter full-area production prediction equation was established using multiple linear regression, enabling rapid production capacity prediction for the entire area. This allows for a comprehensive understanding of production capacity before development, aiding in identifying advantageous development areas and providing robust guidance for subsequent development efforts.