Formation Evaluation Society of Malaysia (FESM)
Formation Evaluation Society of Malaysia (FESM)
“Waterflood Injectivity Loss – A Multidisciplinary Root Cause Case History"
The subject of this talk describes how a multidisciplinary approach, combining elements of production technology, core analysis, oilfield chemistry and geomechanics, was adopted to understanding water injectivity impairment in a sandstone reservoir onshore Indonesia.
Field A initially came on production in 2005, and has produced ~17 MM stb of 35oAPI oil (GOR~300 scf/stb) since then, with an RF ~ 14%. The drive mechanism is primarily solution gas drive, and produced water re-injection was introduced in 2009 for pressure maintenance. With approximately 20 water injection wells currently in the field (along with 40 producers) over the last three years some of the WI wells have been injecting below target, with some reported at zero injectivity. The result is that the water overall injection target cannot be achieved, with a resulting inability to adequately replace voidage and maintain sufficient reservoir pressure, which has fallen to ~400 psi in certain parts of the reservoir (from an initial 1230 psi). Prior to implementing any remedial measures, the operator wished to investigate and identify potential root causes for this lack of injectivity.
Initially suspicion focused on potential formation rock – injection fluid incompatibility, based on the mineralogy of the reservoir. However a number of other causes could also be at fault, either individually or symbiotically. These included the actual quality of the injection water (from multiple sources at a centralized production and water treatment facility), as well as geomechanical issues related to potential sand failure (water hammer) and stress related injectivity loss into the fractured water injectors (the injectors were originally hydraulically fractured production wells).
The forensic analysis required data from a number of different sources: i.e. mineralogy and poroperm from RCA, fluid compatibility from representative core floods, water composition & chemistry from on-site sampling, as well as rock strength and stress data. All of these were acquired following detailed procedures and experiments conducted at various specialised laboratories, after which a final conclusion was arrived at.
This case history illustrates, in common with many other investigations into aspects of well problems and diagnostics, the importance of integrating input from various sources to build a credible, and useful hypothesis.
Rick Lemanczyk is a Principal Petroleum Engineer and Head of Production Optimisation at LEAP Energy, an operating arm of Three60 Energy. He is based in Kuala Lumpur, and has a career spanning over 40 years in various aspects of production technology.
After graduating with a D.Phil. in Physical Chemistry from Oxford University, Rick began his oilfield career working for Schlumberger from 1977-1992 in a variety of positions: wireline engineer, well stimulation R&D department head and regional laboratory manager. Between 1992-94 he was the Enterprise Oil Senior Research Fellow in the Department of Petroleum Engineering at Heriot-Watt University. Between 1994 -2006 he held a variety of positions with Edinburgh Petroleum Services Ltd. (now a Weatherford company), primarily in the areas of well performance modelling and production optimisation. This was followed by 12 years as Principal Petroleum Engineer with Senergy (later Lloyds Register), providing technical support, business development, consulting and training in the areas of production optimization, artificial lift, sand management, well stimulation, completion analysis and formation damage. During this period he also gained considerable experience managing integrated sub-surface field development projects for a number of the company’s clients in South East Asia.
In Three60 Energy Rick’s current role is to coordinate the company’s production technology activity in the Asia Pacific region, which also includes rock properties, reservoir management and production chemistry related activity.
Throughout his oilfield career Rick has been an active member of the Society of Petroleum Engineers and has served as member, co-chairman and chairman on a number of SPE Workshop Technical Committees and Forums. He was nominated as an SPE Distinguished Lecturer in gas lift optimisation for 2010-2011. He has also held the post of adjunct professor at Heriot-Watt University in Malaysia, lecturing on a variety of Production Technology related topics in their Petroleum Engineering M.Sc. programme in 2016-17.
"Understanding Uncertainty in Sanding Potential for a Field with Limited Data"
In any prospect where there is a high potential for sanding, the cost of failure (re-completion, upgrade of surface facilities, schedule delay, etc) is extremely high and, in many cases, can threaten the economic viability of any proposed development. For these reasons, it is critical to determine the potential for sanding with a degree of certainty that might otherwise not be required within a conventional development. This study examines a prospect where the operator was unable to collect sufficient data to significantly reduce the levels of uncertainty and attempts to understand what (if any) development decisions are still possible in such as environment. This work draws exclusively on industry established empirical correlations using log derived data without any calibration from core testing,
In respect to the use of empirical correlations, it is well understood that there is considerable uncertainty associated with their use in the absence of calibrating data. However, while individual authors of correlations have demonstrated the applicability criteria in relation to the data available to them, it is still common practice to utilize these correlations in unconnected fields and formations in a very generalized way. The purpose of this study is show the range of uncertainty associated with their use and establish whether they serve any useful purpose other than to draw very generalised conclusion.
Graeme has over 32 years of industry experience, spanning a well-balanced career path in Petroleum Engineering and Production Technology in both E&P and Service Companies across the globe in operation and projects.
Previously, Graeme has worked in Australia, Brunei, Russia, China, Turkmenistan, Alaska, Mexico, Middle East and UK on various long and short term assignments including new technologies application in well engineering design, integrated operations management, field development planning, production enhancement opportunity identification and delivery, as well as contract strategy, management, negotiation, technical tender preparation and evaluation.
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