All three papers in this month’s issue are very interesting and quite novel. Unconventional hydrocarbon resources, be it shale gas/oil, heavy oil, or bitumen, are the future of our industry. For instance, the shale-gas and shale-oil revolution will allow North America to reach energy independence within the next 5 years. The first two papers in the current issue tackle two of the unconventional resources, heavy oil and shale gas. Both papers propose analyses that facilitate more-efficient and economical production of these resources. The third paper is a formation damage removal paper. The tiny-sized Mn3O4 particles and their high density make them typical agents for high-density drilling and cementing fluids usually used in high-pressure and high-temperature wells. The paper investigates the formation damage removal following the drilling of deep high-temperature wells. I hope you enjoy reading these papers as much as I did.
Heavy-oil reservoirs of the Lloydminster area that straddle the Alberta and Saskatchewan border contain in excess of 30billion bbl of resource in place. The primary recovery technique known as cold heavy-oil production with sand (CHOPS) produces less than 10% of this resource on average. Unfortunately, there is no rigorous numerical simulation method that can model the CHOPS process efficiently, as it is a geomechanically complex process that creates wormholes in the reservoir during the foamy flow of heavy oil in the porous medium. However, a simplified model can be implemented by assuming that the network of wormholes forms fractal patterns.The resulting model in the paper Modelling of Cold Heavy-Oil Production With Sand For Subsequent Thermal/Solvent Injection Applications can be used to history match the CHOPS production and to investigate post-CHOPS recovery technologies.
The shale-gas production (and shale-oil production)revolution has been in the works throughout the last decade in North America.The rest of the world will no doubt follow a similar trend and these resources will soon be a significant contributor to the energy mix. Drilling horizontal wells and hydraulically fracturing them in a number of stages achieve commercial production in such reservoirs. However, it is difficult to optimize this process because of a number of reservoir uncertainties. Given these uncertainties, An Efficient Reservoir-Simulation Approach To Design and Optimize Unconventional Gas Production uses a number of statistical techniques to numerically simulatea series of production scenarios and reach the most economic hydraulic-fracture-treatmentdesign.
High-density fluids at relatively low viscositycan be formulated using Mn3O4 particles to drill deep and high-temperature wells. The spherical shape of these particles improves the plastic viscosity of the drilling fluid. However, the filter cake formed by these particles is difficult to clean up and sometimes the cleanup operations themselves can cause further formation damage. Removal of Manganese Tetraoxide Filter Cake Using a Combination of HCl and Organic Acid proposes a new technique of mixing hydrochloric acid (HCl)with lactic acid for filter cake removal.
Gökhan Coskuner has more than 25 years of industry experience and currently works as Manager of Enhanced Oil Recovery and New Technology in the Heavy Oil and Gas Division of Husky Oil Operations Limited. Previously, he worked as Asset Manager and Reservoir Engineering and Development Lead in oil sands, as a team leader involved in the development and optimization of two deep basin gas fields, and as a reservoir engineer in projects ranging from gas storage to offshore field delineation and development. Before joining Husky Oil, he worked for Agip as a reservoir engineering advisor, for Scientific Software Intercomp as a senior consulting associate, and at Imperial Oil, Shell Canada, and the Petroleum Recovery Institute in various research capacities. He holds a BSc degree from the Middle East Technical University in Turkey, and MSc and PhD degrees from the University of Alberta, all in petroleum engineering. He is currently the Executive Editor of the Journal of Canadian Petroleum Technology. He wasa long-time member of the Journal of Canadian Petroleum Technology Editorial Review Board, a director of the Petroleum Society, and the general chairman for the 2004 Canadian International Petroleum Conference. He was the recipient of the Petroleum Society’s Outstanding Service Award in 2009 and SPE’s Distinguished Member Award recipient in 2013.
Accurate modelling of CHOPS for subsequent enhanced oil recovery processes is a critical task. Modelling of Cold Heavy-Oil Production With Sand For Subsequent Thermal/Solvent Injection Applications initially focuses on this problem, addressing the governingmechanisms during the CHOPS process and provides a quick modelling workflowbased on a step-by-step simulation technique with notion to foamy-oil effects.The inclusion of an integrated fractal wormhole model is detailed, whichincorporates the growing nature of wormholes based on reservoir properties and sand-production data. Then, preliminary post-CHOPS processes are considered through cyclic steam and solvent stimulation to test the compatibility of the suggested modelling approach with thermal and compositional simulators, and as a technical possibility to increase oil recovery from CHOPS reservoirs.
An Efficient Reservoir-Simulation Approach To Design and Optimize Unconventional Gas Production presents an efficient approach to perform a sensitivity study andoptimize shale-gas production by integrating numerical simulation, economicanalysis, design of experiment (DoE), and response surface methodology (RSM). Gas desorption and geomechanics effects are included in the simulations. DoE is used to perform the sensitivity analysis with the purpose of quantifying the rank of important factors and screening insignificant ones. RSM is used to optimize the hydraulic fracture design, considering significant factors in an effort to obtain the maximum net present value under uncertainty conditions. A case study from Barnett shale with eight uncertain parameters with a reasonable range is investigated.
Removal of Manganese Tetraoxide Filter Cake Using a Combination of HCl and Organic Acid discusses the dissolution of filter cake generated by drilling fluids that arebased on manganese tetraoxide particles as a weighting agent using HCl acid,organic acids, and enzymes. Cleanup of Mn3O4-based filter cake is challenging because of the complexity of the system. Three methods to dissolve Mn3O4-based filter cake are outlined. A safe,efficient, and economic technique that uses a lower acid concentration was developed with removal efficiency greater than 85%. This paper will guide petroleum engineers to select the appropriate method to dissolve Mn3O4-basedfilter cake.