Determining the permeability of tight rock with gas transient flow

Petroleum exploration and production from shale formation have gained great momentum throughout the world in the recent decades. Producing hydrocarbons from shale is challenging because of the low porosity and permeability. It is imperative to investigate permeability of the shale formations to better understand the well. Permeability is also one of key parameters in modeling fluids flow in matrix in reservoir simulation. Due to the nature of tight formation, the measurement of shale permeability is time-consuming and cost expensive. These prohibit performing the permeability measurement for a volume of samples. This paper proposes a new method to reduce the measurement-time tremendously thus leading to low-cost and effective core analysis. The new method is more objective than oscillating pulse method, whose permeability is highly uncertain under the condition of low signal-to-noise ratio and is subject to individual interpretation. veloped method evaluates the permeability under unsteady-state flow thus requires short period to determine flow capacity of low permeability rock. It reduces the measurement-time and experimental cost significantly. This new investigation is differentiated from the traditional methods such as Gas Research Institute (GRI), oscillating pulse, or pulse decay methods. Our method can overcome the disadvantages of other methods thus it indeed becomes an important supplement for industry. Further, this method has been rigorously developed from theoretical base, thus it is reliable and accurate for core analysis. The reproducibility of the proposed method is higher than oscillating pulse and pulse-decay methods.