Dynamic varied influence factors of pressure drop in coal reservoir during coalbed methane drainage process

In order to further understand a pressure drop transfer law of the coal reservoir during the coalbed methane drainage process and pressure drop transfer law affected to coalbed methane drainage, based on an observation study on the development and distribution features of the cracking system in the coal reservoir, a C oal cracking system and coal matrix pressure drop transfer geological model were established individually and the pressure drop transfer influence factors and the relati onship of the coal reservoir were analyzed and summarized. The result showed that pressure drop transfer and dynamic variation of the coal reservoir were affected ma inly by the reservoir permeability, water-bearing ability, gas saturation, coal desorption/adsorption features and the well bottom flow pressure and among them, the pres sure drop transfer within the large cracking system of the reservoir would be mainly related to the permeability, water-bearing ability and the well bottom flow pressure. Within the coal matrix, the pressure transfer would be mainly related to the gas saturation and the coal desorption/adsorption features. Due to the reservoir pressure dr op transfer and the influence factors plaid the role in the coalbed methane drainage, the geological parameter features affected to the pressure drop of the reservoir sh ould be understood before the operation of the coalbed methane drainage. The well bottom flow pressure control in the gas drainage process should fully consider the r elationship between the pressure drop influence factors of the reservoir.