Research on the Controlling Factors and Grate Prediction of the Output of Pulverized Coal in Hancheng Block, Eastern Ordos Gas Field

Abstract

According to the 2012s workover treatment statistic in the Hancheng block, the eastern Ordos gas field, the workover caused by pulverized coal accounts for 41.8% of the total, which has seriously affected the continuous and stable drainage. This is one of the main factors which constraint coalbed methane production yield. In this paper, geological factors including the composition of coal petrography, the mechanical strength of coal petrography and coalbody structure destruction and engineering factors including drilling, fracturing and drainage were analyzed to study on the controlling factors on the output of pulverized coal. We conclude that the determinant on output of pulverized coal is the nature of coal seam, however engineering factors cause the output of pulverized coal directly. The root-mean-square amplitude attribute analysis was first used to display the mechanical strength of coal seam. Based on the result, we made the prediction about the possibility of the output of pulverized coal and divided the studying area into four grades. The research on the controlling factors and the prediction of the output of pulverized coal could provide the basis for the prevention and comprehensive treatment of pulverized coal.

Anisotropic Adsorption Swelling and Permeability Characteristics with Injecting CO2 in Coal

“…Accompanied by the in situ stress, the sedimentation and compaction during geological periods change primary and secondary pore morphology. Especially, the mechanical properties of different coal macerals are various; vitrinite has higher brittleness and lower hardness than inertinite. , Pores in low-strength macerals are easily squeezed and form to slit pores with the major axis in the parallel bedding plane direction (PBD) and the minor axis in the vertical bedding plane direction (VBD). This case increases the connectivity of pores in PBD and reduces it in VBD.…”

Study on Key Parameters for Jet Impacting Pulverized Coal Deposited in Coal-Bed Methane Wells

“…CBM well production is a process of drainage and gas production [2][3][4] during which generated pulverized coal particles enter the wellbore with flowing water [5]. Timely discharge of these particles from the wellbore is required to prevent well failures, such as stuck and buried pumps, which significantly affect the continuous drainage and gas production efficiency of CBM and reduce economic benefits [6][7][8]. The discharging of pulverized coal deposited at the bottom of CBM wells has become an important factor for CBM well workover operations.…”