Accurate and rapid tight reservoir permeability measurements are important for unconventional gas production. However, traditional transient pressure pulse attenuation techniques take a long time to measure reservoir cores with nano-Darcy scale permeability. In this study, a novel radial-flow transient technique is proposed to achieve fast and accurate measurements of tight-structure rocks. Two gas containers of the same volume and two pressure pulses of the same size and opposite direction are designed for permeability measurement. Based on this, a mathematical model is established to verify the feasibility of the novel transient technology. Through the analysis of the model, the fluid attenuation law of space and time is compared with that using the traditional technique. The results show that the attenuation of radial fluid pulse is significantly faster; and compared with axial flow attenuation, the measurement time can be reduced more than 10 times. One more advantage of this method is that it can effectively eliminate gas compressed storage and adsorption-induced permeability measurement error. The proposed technique was experimentally verified and proved to be a fast approach for laboratory permeability measurements; meanwhile, the technique is capable of accurately characterizing the gas flow behavior and then reliably used for determining the permeability of gas sink in the range of nano-Darcy scale.
Article highlights
A novel radial-flow transient technique is proposed in this study that offers accurate permeability measurements within a considerably short time frame.
The pressure pulse declines much faster in the radial flow direction than in the axial flow direction and at least a 10-fold reduction in measurement time can be achieved.
The technique can eliminate the effects of the gas compressive storage, and gas sorption on permeability estimation.
The proposed technique provides a fast approach for laboratory permeability measurements; meanwhile.
The technique is reliably used for determining the permeability of gas reservoirs in the range of nano-Darcy scale.
- A novel technique for determining transverse permeability of sorptive reservoirs
- Ziwei Ding - Xi'an University of Science and TechnologyQingbao Tang - Xi'an University of Science and TechnologyRuimin Feng - University of Arkansas at FayettevilleJindui Jia - Xi'an University of Science and TechnologyXiaofei Li - Xi'an University of Science and TechnologyXing Huang - Institute of Rock and Soil MechanicsChaofan Zhang - Xi'an University of Science and Technology
- Geomechanics and geophysics for geo-energy and geo-resources, Vol.8(6), 193
- Springer
- 2021JLM-06 / the Natural Science Basic Research Program Joint Fund Project of Shaanxi Provincial 2015JQ5132 / Natural Science Foundation of Shaanxi Province (http://dx.doi.org/10.13039/501100007128) 51874232; 51504183 / the National Natural Science Foundation of China
- 996868617901851
- Civil and Environmental Engineering
- English
- Journal article