How do you choose the right EOR technique for a given reservoir?
On a very general level, the most common EOR schemes we can quote are: water-based, gas-based, chemical-based and heat-based. Each one of those has sub-sets. Gas-based EOR could be hydrocarbon gas, CO2, H2S, or even N2 in some limited cases. Chemical EOR techniques are even richer. EOR schemes work differently in reservoir conditions, some make oil more mobile, some help to snap oil from the rock surface, some help push the mobilised oil, and there are cases where all mechanisms may work together.
Based on the condition of the reservoir (oil type, pressure, saturation, reservoir rock, etc) suitable EOR schemes are selected; meaning not every scheme works for all reservoirs all the time. Identifying the suitable EOR scheme for your reservoir is where EOR projects start. Within Schlumberger we take that first step very seriously because understanding the reservoir characteristics in its full entirety as well as the field conditions, plays a significant role at that important decision point.
Historically, our industry utilised rather simple statistics-based approaches for the EOR scheme selection. For us, that important step is a full reservoir model-based, multi-domain optimisation exercise. To improve the quality of the decision making we have developed a smart numerical tool, called EORsd which uses your reservoir model and automatically searches the best EOR scheme.
Where is there the most opportunity for growth in terms of EOR technology/techniques?
Our industry has been implementing EOR projects since early 50s; so EOR is not new. Additionally, the fundamentals of EOR physics are well known. However, looking back to all those projects, with a few exceptions, most did not deliver what was originally promised at the early laboratory phase. We carefully examined all those projects and identified how to make EOR project significantly more successful. That analysis provided us the guidance to identify critical EOR technologies & techniques, which has been the basis for Schlumberger’s EOR Vision since 2008. Success in EOR projects, technical and financial, depends on two factors: Fast but optimized project development (from concept to field trial within one year) and once the concept is proven, implementation and operation of effective “monitoring and control” systems throughout the life of the project. New technologies and techniques for EOR will evolve to make those goals a reality. In other words, we believe EOR projects should be designed, implemented and managed way differently than they have in the past.
What are some key technological advancements to EOR?
Building on our EOR Vision, we can list some noteworthy advancements that have been happening in Schlumberger and in the oil industry in general. It is safe to say that finally, reservoir characterisation, EOR design and EOR predictive modelling capabilities are all ready for challenging projects. We have been doing EOR projects for a long time, but only in recent years, partially due to the advancement of computer systems, we can now design EOR projects with the right physics and suitable reservoir characterisation. There are considerable advancements in “pore scale” EOR investigation systems; with the aid of our CoreFlow™ system we can evaluate the recovery behaviour of candidate EOR schemes very early in the project design phase. It is worth mentioning advancements in EOR chemicals; EOR-agents available today are not only significantly more potent than the older ones but also at a lower cost. There are ongoing attempts to right-scale EOR Pilots; those are smart decision systems and field implementation systems. For example, with our MicroPilot™ system we can accelerate field pilot time while honouring the reservoir heterogeneity.
What is going to make EOR projects truly successful is making the “monitoring and controls” part of the field management. Monitoring at different scales has been evolving for different EOR schemes while intelligent completions are also coming along. Advancement in well-logs, sensors, fibre-optics, cross-well technologies and EOR monitoring with field seismic are all exciting technologies. Parallel to the advancement of those individual technologies we have been working on developing new EOR multi-domain integrated project systems which will enable the industry to design and manage new EOR projects properly while getting the value of these technological advancements.
Do companies invest enough into EOR?
Since reservoirs have already passed their prime, operators, especially NOCs, are gradually forced to bring in IOR & EOR. As far as I am concerned, it is not an option anymore, but a part of field management. With limited exploration activity, optimising existing resources is the way to go.
Are there any particular challenges to using EOR techniques in the MENA region?
There is no technical challenge and/or a show-stopper specifically for MENA region. The only difference say between North America and MENA is that decline in North American reservoirs started 20 some years ago. There is only chronological difference, which works for MENA because there are a lot of “lessons learned” from previous EOR projects.
Another apparent challenge is limited CO2 availability in MENA region. Otherwise, I would not be surprised to see a number of IOR/EOR projects growing quickly in MENA.
In your experience, do you think the perception and uptake of EOR changed over the years?
There are more fields are under IOR/EOR operations these days than before. Of course, how fast operators decide to go for EOR still varies from region to region, and from company to company. Companies with long term goals for optimisation of their assets tend to take EOR decisions faster these days than they would have five years ago.
There are two main reasons for that, the first one is “urgency,” which is the key ingredient of reservoir optimisation is more pronounced; and the second reason is that with current technologies EOR projects will be more successful now than they would have been before.
