Differential Fracturing Segmentation And Productivity Simulation Of HF1 CBM Horizontal Well In Tucheng Syncline,Western Guizhou,China

Horizontal well staged fracturing is recognized as the best measure for enhanced CBM productivity in the industry.Differentiated fracturing section is the key to ensure the optimal release of the entire productivity from horizontal well section in coal reservoir.Combined with the design and construction process of HF1 coalbed methane horizontal well in Tucheng syncline,Western Guizhou.Based on the analysis of the geological conditions of the Upper Permian Longtan Formation coalbed methane,combined with the borehole,drilling and logging data of the matching parameter wells to construct the three-dimensional geological model of the target No.3 coal seam and its roof.The CMG software and COMET3 software are used to carry out the numerical analysis of the adaptability of the fracturing parameters and the numerical simulation of the sectional production capacity,and then the fracturing segmentation scheme of the HF1 horizontal well is proposed in this paper According to the rock mechanical properties,physical properties and gas content of the coal seam,the geological differentiation segmentation is studied.Modeling results show;The structure of HF1 well area is simple.No.3 coal seam is developed in the whole area and the stability of coal seam is good.The coal reservoir is in the state of supersaturation,and the e the maximum pressure drop between the heel and toe of the horizontal well is about 3MPa.Gas content ranges from 13.45 m~3/t to 16.04m~3/t,and permeability ranges from 0.0373 m D to0.1078 m D.The numerical analysis results show that the optimal number of fracturing sectionis 7and 8,length varies between 70 and 110m,under the conditions of increased permeability ratios of 10,20,30 and 50.The average gas production of a single fractured sectioni ranges from 1.68 million m~3 to 1.87 million m~3in 10 years.The average daily gas production ranges from 456 to 513m~3/d.The cumulative gas production of the whole horizontal section in 10 years is 135.6×104 million m~3,with an average daily gas production of 3715 m~3/d and an average daily gas production of 9249 m~3/d at the peak stage.According to the results of orthogonal optimization analysis,it is considered that the best gas production effect can be obtained by using 8-stage differentiated staged fracturing.There are 50 figures,26 tables and 118 references in this article.