In S-Field, first oil was in 1975, and the field is undergoing a redevelopment project. Integrated operations (IO) has been identified as part of the redevelopment initiative aiming at providing an asset decision support system. The S-Field operator has identified gravity-assisted simultaneous water and gas injection (GASWAG) as the suitable enhanced oil recovery (EOR) method for the field's reservoir. In implementing a digital oilfield solution addressing the GASWAG performance in S-Field, only the EOR field development plan exists as a guidance. S-Field is the first of its kind to implement EOR GASWAG. This increases the uncertainty of the agreed metrics for measurement and formulas to monitor and implement control of the effectiveness of GASWAG (sweep efficiencies and volume displacement). The scope given is to implement an EOR GASWAG-compatible digital solution that allows flexibility for the users to update their established analysis methods and that uses a web application as a basis for periodic assessment and monitoring within the asset team.
The current implementation of IO at the software level has minimum flexibility to change a workflow. Any changes that are not considered during workflow development and deployment require a specialist from the development team to implement. The described system addresses the challenges in implementing digital solutions for EOR, including introducing more flexibility in adapting to changes in workflows.
The EOR applications include a reservoir simulator to assist the estimation of vertical and areal sweep efficiencies and residual oil displacement in each formation; a geomodel application: to provide graphical interface of the oil, gas, and water distribution in S-Field MN reservoir model; and a data analysis application to provide classical reservoir analysis and method.
To bring the applications together as digital solutions, only applications with application programming interfaces (API) are selected. This is to minimize the development effort. The analysis of EOR GASWAG can be maintained by any user through the current software. This means any changes in the analysis method can be implemented within the existing software interface without affecting the overall solutions. The changes will then be reflected in the corporate-wide implementation (web application) without the presence of a specialist and lengthy administration process.
Applications with API allow extensibility that minimizes the data extraction effort and drives higher utilization time and effort that can be invested in geological models and engineering analysis. In addition, the system minimizes the change management effort because the process leverages current business processes and reduces the cost of investment by using the existing centralized powerful processing computer.
Developing the solution through an analysis application that has the extensibility (API) to other third-party applications has significantly reduced the project implementation duration by half of the initial estimated effort (benchmarked with current project alike).
The Oil Industry has been implementing Integrated Operations (IO), with several fields documenting value achieved from past and present IO initiatives. Largely, these documented IO initiatives have focused on well and equipment performance and general planning. However, Enhanced Oil Recovery (EOR) methods including thermal, chemical and gas injection which are increasingly being pursued in many fields globally require additional meticulous reservoir surveillance to understand and quantify the effectiveness of the EOR scheme which adds to the value of such projects. Interpretation and integration of all available data and processes into clear, structured and reproducible EOR well and reservoir management workflows to support decision making is still challenging due to the variety of disciplines, data acquisition, processing, analysis, and modeling techniques and technologies involved, and the level of collaboration required. Using an EOR-IO framework as a companion to the Reservoir Management Plan (RMP) can help address these challenges and increase the likelihood of project success. This paper describes such an EOR-IO framework which can be adapted for a wide variety of EOR processes as well as any general injection scheme (including water or gas) and presents a case study where this framework was implemented.
The framework is a system for generating a clear framing and mapping of the EOR equipment, data, required analyses and decision processes using an assessment involving all EOR stakeholders and based on the Reservoir Management Plan (RMP). The framework enables all stakeholders to unambiguously understand and agree on how EOR performance will be quantified, what surveillance methods are required and what decisions will need to be taken. The framework facilitates a way for EOR management decision processes to be mapped onto technology-and-people enabled workflows that will help organize data, streamline analysis, define roles and enable efficient management of the EOR implementation in 5 clearly defined layers: Physical, Technology/Infrastructure, Process/Computational, Visualization and Organizational. Depending on the asset and project, the number of workflows may vary but they should fall into one of 3 groups: Operational Group: a system to support implementation of strategy at the operational level using real-time and in-time data. Tactical Group: a system that supports quantification of the overall effectiveness of the EOR scheme in the subsurface in terms of sweep, displacement, pressure, chemical loss, etc. using in-time analysis results. Strategic Group: a system to support identification of situations when an adjustment in EOR strategy is required and enable optimization of the strategy adjustment.
Operational Group: a system to support implementation of strategy at the operational level using real-time and in-time data.
Tactical Group: a system that supports quantification of the overall effectiveness of the EOR scheme in the subsurface in terms of sweep, displacement, pressure, chemical loss, etc. using in-time analysis results.
Strategic Group: a system to support identification of situations when an adjustment in EOR strategy is required and enable optimization of the strategy adjustment.
This framework was successfully applied to a Field in Malaysia where a total of 6 EOR workflows were designed for managing the EOR scheme. The framework was flexible enough to enable design, development and implementation of the workflows to help ensure that the EOR is managed as an integrated, holistic system.
Deposition of solid hydrocarbons such as asphaltene and wax near the wellbore and in the tubing is known to cause decline in the well production performance. Various mitigation methods such as chemical wax inhibition, thermal insulation, and coiled tubing clearance are repetitive and exhaustive. These methods could temporarily remove deposits but not prevent them from reoccurrence. On the other hand, the thermo-chemical method utilizing acid-base reactions seems to be offering the most effective and simple solution to the problem. Reaction products and heat from the acid-base reactions could be utilized to dissolve and disperse wax or asphaltene deposition in addition to changing the wettability profile. The present study is to evaluate the performance of acidized amines for mitigating formation damage and improve oil recovery in the Penara Field, offshore Peninsular Malaysia. Wells in the field have been recording massive production decline of more than 5000 stb/d despite continuous treatment of pour point depressant, wax dispersant, de-emulsifier and frequent tubing clearance activities.
Physical observation and interfacial tension measurement were carried out to qualitatively and quantitatively measure the performance of the acidized amines. Improvement in the oil recovery was measured through coreflooding test. The study found that acidized amines by-products dispersed the suspended wax solid and prevented it from re-depositing after 48 hours. Thus, oil recovery increased to 51.3 % for non waxy-liquid crude and 13.0 % for waxy-gelled crude. These findings from the laboratory were further validated by production optimization using Wellflo.
The thermochemical method utilizing acidized amines is simple and yet experimentally proved to be effective in solving the wax related problem. Considering the reserve potential in the Penara Field and supported by sufficient well data, the incremental production of 22 % could be predicted.