Reservoir Evaluation and Development ›› 2018, Vol. 8 ›› Issue (2): 22-29.

• Reservoir Evaluation • Previous Articles     Next Articles

Pressure response analysis of large scale series double fracture-cavity carbonate reservoir

Xiong Yu1,Ye Haifeng1,Cai Mingjin2,Niu Xinnian2   

  1. 1.Southwest Petroleum University, Chengdu, Sichuan 610500, China
    2. PetroChina Tarim Oilfield Company, Korla, Xinjiang 841000, China
  • Received:2017-05-16 Online:2018-04-30 Published:2018-04-30


The fracture-cavity carbonate reservoir has large scale and discontinuous medium, and its main reservoir space is composed of fractures and caverns. Many wells are independent fractured-cavity systems, and most of them connect macrofractures to the wellbore. These wells are separate fracture-cavity cells which connect with one or two big cavities in series by fracture network, so the actual flow process of the reservoir does not match the result obtained by adopting traditional continuum theory. An analytical mathematic model is presented by considering the fracture network between well-cavity and cavity-cavity as one dimensional linear fracture, and other fracture communication flow exist in the periphery of the cavity(away from wellbore). Accordingly, the linear-in-series well test mathematic model with fracture connecting two cavity systems is established, and the model introduces the conception of transient flow and channeling flow of multiple media. The Transient conduction principle and Laplace transform are used to solve the mathematical model, and the dimensionless bottom hole pressure type curves are plotted in real space by using the improved Stehfest numerical inversion. The analysis of the sensitivity of cave parameters shows that the model can correctly reflect the relation between flow control factor and geological factor. Application examples indicate that this model can correctly explain wellbore storage factor, skin effect, the permeability of fracture system and cavity system, and the geometric parameters of fracture and cavity.

Key words: fracture-cavity reservoir, drilling fracture, double fractured-cavity in series, mathematical model, type curves analysis

CLC Number: 

  • TE372