Technologies and countermeasures for gas recovery enhancement

AbstractSince 2000, China has been ranked as one of the top countries in gas production. Nevertheless, the domestic gas production can hardly satisfy the need of national economic development. Besides, an increasing number of gas fields have come to the middle or late development stages, and most gas reservoirs have low recovery efficiency due to the low permeability and water drive nature. Therefore, gas recovery enhancement has become an urgent issue. At present, the oil recovery enhancement is well defined, and there are methods describing the remaining oil and a complete set of mature EOR (enhanced oil recovery) technologies. However, the definition and description of EGR (enhanced gas recovery) are still undermined, and the description method for the distribution of residual gas and EGR technologies are almost unavailable. In view of this, by reviewing a wealth of related literatures, we defined EGR and also described the remaining gas distribution based on the remaining gas abundance. In addition, collecting three typical types (low-permeability, condensate and edge/bottom water) of major gas reservoirs developed both at home and abroad, we summarized the geological and development characteristics, and found out the obstructions in the development. In response, we concluded and analyzed the relevant technologies and methods for enhancing the gas recovery of such reservoirs, and proposed the suggestions about EGR technology development, which provides a significant reference and popularization basis for EGR measures in fields