Hydraulic fracturing in an unconventional naturally fractured reservoir: a numerical and experimental study
Mohammad Sarmadivaleh A , Vamegh Rasouli A and Noufal Kakode Shihab ACurtin University of Technology
The APPEA Journal 51(1) 507-518 https://doi.org/10.1071/AJ10034
Published: 2011
Abstract
Natural fractures play a vital role in the production of low permeability reservoirs when no stimulation techniques are used. The characteristics of natural fractures, together with their pattern that defines how they communicate with each other and to the wellbore, will govern how effectively they can contribute in production enhancement. In most occasions, however, hydraulic fracturing must be used as a remedy to have an economical production rate. Fraccing itself is a complicated process, but would be further complicated when it is practiced in a discontinuous medium.
Depending on the properties of the natural fracture(s) and operational condition of the fraccing job, opening, offsetting, crossing or arresting are possible interactions that may happen when an induced fracture reaches a natural discontinuity. In this study, the simplest interaction case with an angle of approach of 90° was studied through both laboratory experiments and numerical modelling. The experiments were carried out under real-triaxial stress conditions using a true-triaxial stress cell (TTSC). Two cement blocks of 20 cm with artificially-made natural fractures were used in this study. The cuts in one sample were filled with weak glue, whereas stiff cement was used in the second sample. The results indicate the importance of interface filling material properties in dominating the interaction mechanism. The numerical models built to simulate these two lab scenarios used particle flow code 2D (PFC2D). The model was tuned and validated against the experimental observations and a good agreement observed between the results of the two approaches.
Mohammad Sarmadivaleh is a PhD candidate at Curtin University of Technology, Perth. He is working on a numerical and experimental study of the Interaction of an induced hydraulic fracture with a natural interface. Mohammad holds a bachelor of science in petroleum engineering (reservoir engineering), a master of science in drilling and production engineering from Petroleum University of Technology (PUT), Iran and a master of engineering in petroleum well engineering from Curtin University of Technology. mohammad.sarmadivaleh@postgrad.curtin.edu.au |
Vamegh Rasouli is an associate professor at the department of petroleum engineering. He is a Chartered Professional Engineer (CPEng) and is a registered engineer with the National Professional Engineers Register (NPER) of Australia. After completing his PhD in 2002 from Imperial College, London, Vamegh took up the position of assistant professor in the department of petroleum engineering at Amirkabir University of Technology (Iran). In 2006 Vamegh joined the department of petroleum engineering at Curtin University to support the delivery of the department’s master of petroleum well engineering—and to carry out research in his specialist area of wellbore stability, sanding, hydraulic fracturing, etctera. He established the Curtin Petroleum Geomechanics Group (CPGG); it has completed number of successful research and consulting projects. He now supervises six PhD students and numerous master students. Vamegh has also been a consulting engineer on various geomechanics-related projects with Schlumberger’s Data and Consulting Services (DCS) in Perth. v.rasouli@curtin.edu.au |
Noufal Kakode Shihab is a Master of Engineering Science student in petroleum engineering at Curtin University of Technology, Perth. He is now conducting a research project on numerical modelling of hydraulic fracturing at the Department of Petroleum Engineering, Curtin University of Technology, Perth. Noufal holds a BSc in mechanical engineering from the University of Kerala, India. noufal.kakodeshihab@postgrad.curtin.edu.au |
