Horizontal multistage fracturing required to achieve production targets
Baharyia formation is a common reservoir in the western desert of Egypt characterized as a low quality sand and a heterogeneous reservoir. It is comprised of fine-grained sandstone, thin, laminated, sand-poor parasequences with shale interbeds. The heterogeneity and low permeability of Upper Baharyia reservoirs are the main challenges to maintain economical well productivity.
The interest in developing low permeability reservoirs has led to favorable economics achieved by the advancements in horizontal well drilling and hydraulic fracturing technologies, holding promises for increasing production by increasing the contact area with the producing interval. Subsequently, it became apparent that stimulated vertical wellbore contact alone was not always sufficient to provide the production increases expected, and therefore horizontals using Multistage Hydraulic fracturing (MSHF) stimulation treatments are required to achieve production targets.
In order to economically develop reservoir resources a comprehensive parametric study recently conducted in the reservoir has documented critical results, showing the productivity index ratio between fractured vertical and MSHF horizontal wells illustrates the improvement to be obtained from higher reservoir contact and MSHF.
The primary well production analysis revealed that the cumulative production from the horizontal well was enhanced from 37% to 70% of recoverable reserves. The recovery factor was doubled compared to verticals. From the production analogy reducing well count from three vertical wells to one horizontal well has direct economic benefits through reducing the installed artificial lift strings, number of workovers, and expensive artificial lift equipment repairs.
This paper takes a multidisciplinary approach to better understand productivity enhancements of low permeability oil reservoirs in the western desert of Egypt through a detailed analysis of well performances and successful implementation of MSHF in horizontal wells to maximize drainage volume around the well and economics of reduced well count to serve as guidelines for other operators who may be facing similar challenges.
Source: SPE Middle East Unconventional Resources Conference and Exhibition, 26-28 January 2015, Muscat, Oman
Authors: Amro Ahmad Hassan (Halliburton) | Ahmed Ali Mohamed Abdel Meguid (Halliburton) | Sayed Arshad Waheed (Halliburton) | Mohamed Salah (Khalda Petroleum Company) | Essam Abdel Karim (Khalda Petroleum Company)