Reservoir engineering, an essential link in the E&P chain
Reservoir activity is a determining stage in the Exploration-Production chain: that of studying discoveries, with a view to their development and production start-up. Reservoir teams are therefore involved in the majority of the studies and operations which punctuate the life of a hydrocarbon field, as it moves through the decision to develop based on particularly meticulous technical studies. What is required from them? Deliver the best possible results, aimed at the best produced volumes vs cost and delay ratios.
Total's reservoir teams have acquired a wealth of experience over the years in extremely varied E&P assets. They have often been pioneers in a number of fields: seismic processing, seismic inversion, 4D repetitive seismic, uncertainties, geostatistics, reservoir simulations of complex recovery mechanisms, the latest laboratory techniques, etc. This experience has allowed them to develop and permanently improve control of the main uncertainties, the sine qua non for success.
Moho deep offshore oilfield (Congo).
Reservoir simulation scheme.
Significant technical challenges
While a great number of deposits and prospects that are the easiest to explore have already been drilled and developed, current hydrocarbon production conditions require still greater technical control and permanently greater ability to meet new challenges.
Today, Total is a recognized specialist in difficult environments, in which it has acquired unparalleled experience: deep and ultra-deep offshore oilfields, highly viscous fluids that are difficult to move, like in Venezuela or Canada: HP/HT reservoirs, like in the United Kingdom; non-conventional reservoirs of tight gases and shale gases, like in China, the USA and Argentina.
Total's reservoir teams are also an international reference for improved recovery, as evidenced by the deep offshore polymers project in Dalia in Angola or the SP injection project (Surfactant Polymer) in a HPHT environment on ABK, in the United Arab Emirates, a real challenge in the profession. Not forgetting the development of carbonates with particular flow characteristics, such as in Brazil.
To respond to the increasing complexity of these environments and lead their successful development, Total's reservoir activity is based on the ability of these staff to integrate complex and diverse data streams with perfect technical control based on proprietary tools.
Economic and environmental challenges
But technical challenges are not the only ones to be met. In a tense economic situation, due to the instability of crude oil price and sluggish world growth, the uncertainties have never been as great. Total's reservoir teams concentrate their efforts on achieving the right results in all projects, always reducing technical uncertainties further and optimising production according to the characteristics of reservoirs and contractual conditions and ultimately contributing to the necessary reduction in development costs.
As a responsible player, Total's reservoir engineering acts in line with the Group's commitments to the CCUS (Carbon Capture, Use and Storage) principles and for the permanent cessation of gas flaring and in favour of the COP21 scenario aimed at a maximum global warming of 2°C. Everything is done to comply rigorously with current regulations, populations rights and welfare, marine and land fauna protection and eco-systems equilibrium. These major challenges lead Total to systematically explore developments which minimize the impact of our operations on the environment.
Reservoir engineering: being present at all stages in the life of a field
Reservoir teams are involved in all phases concerning potential then actual deposits.
- During the exploration phase, they are initially involved in technical and economic studies of the largest and most strategic prospects. Their role consists of establishing notional field development plans and forecasting potential production profiles, according to data provided by Exploration.
- During the Appraisal phase of a discovery (phase 1), they work with Exploration to delineate the extent of the deposit, obtain precise details of the nature of the fluids in place and reduce the numerous uncertainties, both on the position of contacts and the communications between sedimentary bodies e.g., in order to result in an initial estimate of resources.
- During development architecture studies, from the Preliminary phase (phase 2) through to the Project phase, multi-discipline project teams are put together. They comprise geophysicists, geologists, reservoir engineers, petroleum architects, drillers, operators, economists, etc. These teams are responsible for defining the most robust and economical FDPs (Field Development Plan), given the uncertainties identified. They may also construct additional development plans for a field already in production or a field discovered by another operator.
- During these study phases (Preliminary, Conceptual, Pre-project, Project),Total's reservoir staff always works together with teams of specialists in various fields to select and then implement the relevant development plan: seismic processing and interpretation, diagraphic interpretations or well tests, geological modeling, petrophysics, fluid PVT analyses, recovery mechanisms, dynamic simulations, monitoring, well performance, drillers and production engineers, etc.
Reservoir engineering studies consist of establishing robust development plans (selection of suitable recovery mechanisms, location of wells) and the most relevant production profiles possible, that architects need to size surface facilities; then come the economists. Depending on the study phase, these studies must be adapted not only to fixed time frames, but also to the nature of the available data (the type and volume of which can considerably vary).
- During the Project phase, Reservoir studies consist of specifying production profiles, preparing well drilling programs, the sequences for drilling and monitoring in order to de-risk remaining uncertainties.
- Finally, Reservoir teams remain active, both within the subsidiary and at head office, to ensure that new developments start correctly, and then manage them during the production phase, while remaining proactive for studying and then proposing additional development phases (infill wells, satellite fields, etc.). They are also responsible for reviewing assessments of resources and reserves throughout the life of a field.
Three assets for reducing uncertainties
Our integrated reservoir studies workflow.
U like advanced facies modelling tool (geological simulation).
The Sismage-CIG platform: from interpretation to geological model.
Integrated teams to improve performance
In a technical and economical context which is constantly changing, Total's Reservoir teams aim to ensure that all the provisional and operational decisions taken are optimized. For this, they rely on four major performance elements.
- The use of a proven studies and validation process: a clear vision of the objectives, guided by a validated methodology , open to the inclusion of innovations, allows them to anticipate the work required at the earliest possible stage, during the Appraisal phase and then during all the development study and project execution phases.
- Integrating the various Reservoir professions (geophysics, geology, reservoir) is one of Total's recognized strengths. The essential integration of all specialties, achieved through decompartmentalisation and bringing together multiple skills, ensures that teams have the ability to work together towards the same objective - excellence.
- A quality approach that makes no concessions: at the same time, Reservoir teams epitomize the Group's quality approach, ensuring that results match the objectives set along with controlling costs and time scales, with a guarantee of actual adding value.
- A rich array of unifying tools: these resources, such as the SISMAGE®-CIG integrated geo-sciences claim and linked, comprehensive databases, allow the teams to achieve their ambitions in terms of quality, efficiency and operational speed.
Relevant technical approaches and a great capacity for interpreting data
One of Total's particular features is its ability to develop internally the tools necessary for controlling geophysics and geology and reservoir techniques (such as simulating recovery mechanisms and flows within the reservoir).
Thanks to the skills and versatility of its specialists, the speed of development and application of new tools or R&D concepts is particularly efficient.
Reservoir teams are thus able to solve the new industrial problems that occur with each new discovery or development. We can give the example of:
- The use of the 4D seismic on block B17 in Angola;
- New core measurement protocols in order to characterize non consolidated reservoirs in Uganda or shale gas in Argentina;
- The Polymer pilot on Petrocedeno field in Venezuela
The tools developed by the Reservoir R&D are adapted to these varied and often previously un-encountered situations. Reservoir teams learnt for a long time how to establish a suitable acquisition, processing and data interpretation program (for example in terms of characterization of heterogeneities) in any type of petroleum environment (from the simplest to the most complex).
They are also very efficient in the field of data processing. With considerable ability to manage process and interpret large data flows, they design monitoring plans suited to the phases before and after entry into production. This constant monitoring relates to both static data (knowledge of the thermodynamic properties of fluids and reservoir characteristics, of sedimentary or structural heterogeneities) and dynamic data (understanding flows within the reservoir, taking subsea and surface flows into consideration).
The tools, but also the method
Total Reservoir crews know how to adapt their methodology to any situation. Thanks to their integrated methods and tools and their ability to envisage multiple scenarios, they make constant progress towards the early reduction of uncertainties and the greatest possible consideration of risks throughout all the development phases. The development concepts put forward thus gain in strength, right from the end of the petroleum architecture conceptual phase.
Their technological edge also enables them to offer original, cost-effective technical solutions in even the most difficult cases.
The methodological approach evolves towards greater integration (thus for coupled simulations between the reservoir model and the surface network model).
The quality approach implemented in the Reservoir studies is also one of the reasons for their success, illustrated by their relevance at the lowest cost. It is based on an efficient "in house" reference base, ensuring good performance and right solutions in the prevailing economic conditions and without any concession where safety is concerned. This reference base, with its Company rules and its guides and manuals, is one of the distinctive assets, for example for preserving the integrity of fields through scrupulously complying with injection pressure limits not to be exceeded.
This quality process, in the service of our customers, also increases the reliability of the reserves validation process.
Efficient R&D and training
Total maintains a proactive and diversified R&D strategy, supported by a considerable budget, including during times when economic conditions are tough. This strategy includes improving and adapting tools, software and hardware, to meet operational needs: new simulation or seismic processing algorithms, increasing the power of the super calculator to meet seismic processing and interpretation and reservoir simulations challenges, new methods for characterizing reservoirs, technologies adapted to the unconventional, deep offshore, etc.
This strategy is also accompanied by the continuous internal training of personnel in these new tools and the hiring of top level specialists.
The complementary nature of Reservoir teams and R&D staff who share the same needs, is essential for the design and development of new tools. This close relationship is strengthened by a special style of organization: personnel involved in R&D programs with low technological maturity and teams working on Platforms for Innovative Technologies, closer to the operational side, work continuously in synergy. This model allows a rapid transfer of research technology to studies and operations; that reduces the time between a method or a new technology being designed and its operational application, by monitoring the new tools increasing maturity process, measured on the TRL scale (Technology Readiness Level).
To supplement and improve skills internally or share development risks, Total, recognized as a high-tech operator, especially in technically difficult environments, has formed numerous partnerships. So, the Reservoir activity works together with independent operating teams and NOCs (National Oil Companies) to face up to the numerous petroleum development challenges. In this way, it has proven its ability to respond to the requirements of its NOC customers and international industrial partners. Depending on the terms of a partnership, it is possible for them to access training from Total and OJTs, and, at the same time, have Total personnel attached to and fully immersed in their teams (mentoring).