Well Testing Analysis of Horizontal Open Hole Multistage Fracturing Wells in Tight Gas Condensate Reservoirs in Saudi Arabia to Characterize Production Performance and Fracture Behavior: Case Studies

Abstract

Abstract Horizontal Open Hole multistage fracturing (OHMSF) completion is the preferred completion to develop the tight and heterogeneous carbonate reservoir. Production data analyses and pressure transient tests are systematically and routinely conducted on these wells to determine the well productivity indices and evaluate key reservoir and fracture parameters. The OHMSF completions have been implemented since 2009 and have showed remarkable results compared to other completions and stimulation strategies such as vertical wells with single or multistage fracturing and open hole multilateral wells with maximum reservoir contacts. This paper presents the modeling and interpretation of production and actual pressure transient responses of horizontal OHMSF wells that were drilled in both the minimum horizontal stress (σmin) direction and the maximum horizontal stress (σmax) directions to assess the production and fracture behavior. Creating transverse fractures has shown better productivity compared to the longitudinal fractures in terms of production performance, which is corroborated in the paper through pressure transient analyses (PTA) and results from field data. The paper evaluates the impact of the fracture parameters such as fracture half length, conductivity, orientation, and number of fractures on production and pressure behavior. Well testing and production analyses tools are very powerful techniques to assess and compare different types of flow regimes for horizontal OHMSF wells drilled in different azimuth directions. This paper discusses and explains the different derivative shapes captured during well tests and compares these to the simulated and theoretical models. Also, the transmissibility values obtained from the mini falloff (MFO) test following during the fracture injectivity operations are compared with the flow capacity values calculated from the PTA. Challenges impacting pressure transient responses such as high wellbore storage are addressed in the paper and proper planning and use of best practices in the PTA to obtain accurate results are discussed and presented.