|
|
|
| Productivity Analysis for Acid Fracturing Well with Consideration of the Effect of Acid Wormholing Zone and Variable Gas PVT Parameter |
| XIONG Jian1, FENG Yanli2, ZHANG Nan3 |
| 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China;2. Geology Research Institute of the First Production of Qinghai Oilfield, Haixi 816400, Qinghai Province, China;3. Geology Research Institute of Greatwall Drilling Company, Panjin 124010, Liaoning Province, China |
|
|
|
|
Abstract: In view of the variations of the PVT parameters in the acid wormholing zone and the gas with the pressure, based on the change of the fluid flow pattern after fracturing, using the steady seepage theory, with the consideration of the influence of the start-up pressure gradient, the slippage effect and the stress sensitivity in the low-permeability gas reservoirs, a gas well productivity prediction model is established for the finite conductivity vertical acid fracture wells. The influence of some factors on the productivity is analyzed by using examples. It is shown that the gas PVT behavior has a great influence on the gas well production in the low flowing pressure stage, but has little influence on the gas well production in the high flowing pressure stage. With the consideration of the variation of the gas PVT behavior and the gas PVT invariable behavior, the start-up pressure gradient, the stress sensitivity and the slippage effect have similar influences on the gas well productivity, but their working mechanisms are different. The longer the length of the acidizing wormhole is in the acid wormholing zone, the more the extent of the gas well productivity is decreased. The more the permeability is in the acid wormholing zone, the lesser the decreasing extent of the gas well productivity.
|
|
Received: 15 October 2012
|
|
|
|
|
|
|
|
|
2012, Vol. 30 
