|
Mid-deep formations of Ying-Qiong Basin are characterized as deep, tight, high-temperature, and overpressure, the fluids in which generally contain CO2, so high-pressure physical property parameters of natural gas and stress sensitivity of low permeability reservoir should be considered in the well testing method. Thus, based on the Standing-Katz chart, the high-pressure natural gas physical property parameter calculation method is optimized that are suitable for reservoirs containing CO2, and taking the influence of pressure on seepage into account, a well testing analysis model considering stress sensitivity is established. Results show that when CO2 content is lower than 5%, the most properly high-pressure natural gas physical property parameter calculation method is LXF method, when CO2 content is higher than 5%, the most properly method is BB method. During radial flow period, the pressure derivative curves of drawdown test goes upwards gradually with the duration of production, and the greater is the stress sensitivity factor, the shorter is the distance between the pressure curves and the pressure derivative curves. While as for buildup test, the pressure derivative curves goes downwards gradually with duration of shut-in, and the greater is the stress sensitivity factor, the greater is the distance between the pressure curves and the pressure derivative curves.
|
