Development of a new approach for hydraulic fracturing in tight sand with pre-existing natural fractures
Kunakorn Pokalai A B , David Kulikowski A B , Raymond L. JohnsonA Australian School of Petroleum
B The University of Adelaide
C Unconventional Reservoir Solutions
The APPEA Journal 56(1) 225-238 https://doi.org/10.1071/AJ15017
Published: 2016
Abstract
Hydraulic fracturing in tight gas reservoirs has been performed in the Cooper Basin for decades in reservoirs containing high stress and pre-existing natural fractures, especially near faults. The hydraulic fracture is affected by factors such as tortuosity, high entry pressures, and the rock fabric including natural fractures. These factors cause fracture plane rotation and complexities, leading to fracture disconnection or reduced proppant placement during the treatment.
In this paper, rock properties are estimated for a targeted formation using well logs to create a geomechanical model. Natural fracture and stress azimuths within the interval were interpreted from borehole image logs. The image log interpretations inferred that fissures are oriented 30–60° relative to the maximum horizontal stress. Next, diagnostic fracture injection test (DFIT) data was used with the poro-elastic stress equations to predict tectonic strains. Finally, the geomechanical model was history-matched with a planar 3D hydraulic fracturing simulator, and gave more insight into fracture propagation in an environment of pre-existing natural fractures.
The natural fracture azimuths and calibrated geomechanical model are input into a framework to evaluate varying scenarios that might result based on a vertical or inclined well design. A well design is proposed based on the natural fracture orientation relative to the hydraulic fracture that minimises complexity to optimise proppant placement. In addition, further models and diagnostics are proposed to aid predicting the hydraulically induced fracture geometry, its impact on gas production, and optimising wellbore trajectory to positively interact with pre-existing natural fractures.
Kunakorn Pokalai is presently a production engineering PhD candidate at the University of Adelaide. He has a BEng in petrochemical engineering from Silpakorn University (Thailand), and completed a Graduate Certificate in Management, and a master’s in petroleum engineering from the University of Adelaide. Kunakorn’s research interests are in the simulation of unconventional reservoirs and hydraulic fracturing. He mainly focuses on the issue of fracturing fluid flowback in the Cooper Basin. He was the recipient of the prestigious AAPG Imperial Barrel Award in the Asia Pacific Region in 2014. Member: SPE and AAPG. kunakorn.pokalai@adelaide.edu.au |
David Kulikowski holds a BSc (Honours) in petroleum geoscience and geophysics, and is now completing a PhD by publication in structural geology at the Australian School of Petroleum, University of Adelaide. David’s main research interests are in better understanding the structural and stress history of the Cooper Basin through the integration of micro- (calcite twinning), meso- (natural fractures) and macro-scale (faults) structural data. David is a recipient of the 2015 American Association of Petroleum Geologists (AAPG) Grants-in-Aid Foundation Scholarship. He was also a team member in the first Australian team to win the prestigious Asia-Pacific Region AAPG Imperial Barrel Award (IBA) in 2014. During the early stages of his PhD, David was employed as a part-time technical assistant at Santos in the gas production and optimisation engineering team. david.kulikowski@adelaide.edu.au |
Raymond (Ray) L. Johnson, Jr. is presently Principal at Unconventional Reservoir Solutions, and serves as Adjunct Associate Professor at The University of Adelaide, and Senior Lecturer at The University of Queensland. He has a PhD in mining engineering, a MSc in petroleum engineering, a Graduate Diploma in information technology, and a BA in chemistry. Ray has been active in the Society of Petroleum Engineers (SPE) as past Chair of the SPE Queensland Section, and served as 2013 and 2015 technical co-Chair of the SPE Unconventional Reservoir Conference and Exhibition Asia Pacific. He has authored, co-authored and presented numerous papers on unconventional reservoir technologies at SPE and APPEA conferences, as well as published in peer-reviewed journals. ray.johnson@adelaide.edu.au |
Manouchehr (Manny) Haghighi is Associate Professor of Petroleum Engineering. His research and teaching focus is on unconventional reservoirs, reservoir simulation, well testing, and formation evaluation. He has supervised more than 40 MSc and 10 PhD students. Before joining the University of Adelaide in 2009, Manouchehr was Associate Professor of Petroleum Engineering at the University of Tehran (Iran). From 2000–07 he was Head of the petroleum engineering program at the University of Tehran. In 2000, Manouchehr established Simtech, a consulting company for the integrated reservoir simulation. He has been project director of several full field simulation projects for oil and gas reservoirs. From 1995 to 2000, Manouchehr was working with the National Iranian Oil Company (NIOC) and was the director of a program for training NIOC staff at several universities in the US, UK, Canada, France, Australia and Norway. Manouchehr was a visiting professor at the University of Calgary from 2007–08. Manouchehr has published more than 80 articles in peer review journals or presented in international conferences. He has served as a reviewer for different journals such as the Journal of Petroleum Science and Engineering. Member: SPE. manouchehr.haghighi@adelaide.edu.au |
Dennis Cooke has a PhD in geophysics from the Colorado School of Mines, and more than 25 years of experience in oil and gas exploration and development. He is a past-president of the Australian Society of Exploration Geophysicists (ASEG), and a former vice president of the Society of Exploration Geophysicists (SEG). Dennis owns and operates ZDAC Geophysical Technology, which provides technology and services for seismic inversion and reservoir characterisation. He is an Adjunct Assistant Professor at the University of Adelaide’s Australian School of Petroleum. dennis.cooke@adelaide.edu.au |
