Oil and Gas Production : Resource Centre

Subsidizing the Oil Reserves and Increasing Reserve Production

Moustafa Mohamed Gammal
Posted: 08/25/2010

Oil and Gas Production Content Series

The current world energy resources are getting now dry. Therefore there must be devised methods to increase reservoirs capacities, and thus the enhanced oil recovery (EOR) will be the best endeavor to solve energy resources crises.

Before 1970, natural gas was the primary injection used to maintain pressure in low gas-to-oil ratio reservoirs. By re-injecting natural gas into the reservoir, the oil producer was able to either increase or maintain current oil production rates. Afterwards, natural gas became unavailable in some areas, as well as too expensive to be used for re-injection. However, natural gas is still being used when there is no economical way to recover it commercially.



This article summarizes the different current methods of EOR and improved oil recovery (IOR). The IOR is considered technically to be a part of the EOR. This is due to using only CO2 gases as injection medium to improve the oil recovery, while the EOR is a global means for enhanced oil recovery.

EOR

EOR as thus gives the oil and gas industries boost and will increase the productivity of the wells. Yet there is no one rule to apply a definite EOR single method to all wells. Instead it should be tailored within the experience of the operators to utilize the suitable best alternative out of several alternatives. This would reduce errors as well as remove obstacles and lead to better management decisions.

Monitoring Levels of Oil and Gas Wells

In the ideal situation, the electrical system monitors the oil extraction and then matches the pump’s speed via a load cell mounted on the well rod. Today’s pump-off controller moni­tors the amount of oil being extracted, and then uses those measurements to match the speed of the motor/pump to the reservoir. One approach is to use a programmable logic con­troller (PLC) card that mounts directly onto the VFD and pro­vides this information. The card not only provides the control needed but also reduces the enclosure space required.

Why Should We Apply EOR?

EOR produces more oil and more need for consumption of CO2. On the other hand, the more oil we use, the less tar we need. If the EOR confirms cost estimates and feasibility, then the EOR technology will globally be used to increase oil and gas recovery upstream productions. Because:

  • Even though petroleum and natural gas resources are finite, they remain among the most important sources of energy in the world. With the decline of hydrocarbon reserves, improved recovery of these resources to boost production is becoming increasingly important.
  • Most improved oil recovery projects involve the flow of three phases, where a gas, which could be air, natural gas, carbon dioxide (CO2) or steam, is injected into a reservoir containing oil and water. In particular, the use of CO2 injection into mature oil fields is likely to become increasingly common not only to enhance oil recovery but for storage of CO2 emitted from power stations and other large point sources.
  • In addition, estimates of reserves from reservoirs in the Middle East increased significantly, leading to the expectation that the oil and gas supplies would be enhanced to be plentiful.
  • Although large volumes of oil remain in mature reservoirs, the oil will not be produced in large quantities by EOR processes unless these processes can compete economically with the cost of oil production from conventional sources.

Benefits and Gains from EOR Technology

Some of the economic and environmental dividends that EOR will provide include:

  • Creation of more than 3 million new jobs in only the US
  • More than $1 trillion in economic impacts
  • Elimination or reduction of carbon emissions and greenhouse gas emissions as well as plastic rubbish containments
  • Significant reductions of oil imports
  • Reduction of energy prices, which would save consumers as much as $50 billion on their energy bills
  • Stimulation of rural economies
  • Conservation of natural gas supplies
  • Creation of a clean, safe energy future

EOR Methods Currently Used

Fig. 1 shows that there are mainly five methods currently applied in EOR. Each of the five families is being divided to sub families, the most used of which is the chemical means. (Click on diagram to enlarge.)

Fig, 1: EOR methods now in current use

Associated EOR Displacement Phases

  • In addition to the measurement of saturations, pressure drops, and fluxes in three flowing phases, there are an infinite number of different displacement paths.
  • Therefore it is impractical to measure relative permeability for all possible three-phase displacements that may occur in reservoir.

Global Recommendations

To gain improvement in IEOR "Improved Enhanced Oil Recovery" and IEGR "Improved Enhanced Gas Recovery" the following recommendations must be thoroughly fulfilled.

Recommendation 1: Assessment of hazards associated with oil spill effects should be investigated and safety measures must be implemented.

To assess the general magnitude of expected hazard levels, a limited sensitivity analysis has to be performed using simplified models for a range of spill volumes. The spill volumes are then to be based on potential breaches from credible accidental and intentional threats. When not conducted for a specific site, the analyses must provide examples of general considerations for hazards and risks; while thermal hazards can exist beyond 1600m they are generally lower in most cases.

Recommendation 2: Use the proper animation model and analyze the predicted hazard impacts.

Current spill and dispersion modeling and analysis techniques have limitations. In addition, variations exist in location-specific conditions that influence dispersion, such as terrain, weather conditions, waves, currents and the presence of obstacles. Therefore, it is sensible to provide guidance on the general range of hazards for potential spills rather than suggest a specific, maximum hazard guideline.

Recommendation 3: Estimate the associated hazards and put the correct scenarios and alternative solutions. This is to know for sure that the estimates of worldwide oil recovery factors range from 27 percent to 40 percent. The resulted EOR Hazards should be kept to a minimum level. Otherwise, people, major commercial/industrial areas or other critical infrastructure elements, such as chemical plants, refineries, bridges or tunnels, or national icons located within portions of this zone could be seriously affected.

Recommendation 4: Viscosity vs. depth relationship.

The EOR should be based on technical terms taking viscosity of the oil into consideration. Therefore a plot shall be prepared for the oil viscosity versus reservoir depth illustrates the three main families of EOR:

  • Thermal, most commonly steam injection
  • Miscible or immiscible gas injection
  • Chemical, which include polymer and surfactants

The three techniques have different applications and success factors, and some are more mature than others, so each requires its own approach and area of technology focus and applications.

Recommendation 5: Tailor and design the proper EOR for the distinguished reservoir.

Enhanced oil recovery (EOR) processes are as varied as the number of fields to which they are applied. Each field and project has unique char­acteristics that must be identified to design the best approach to recover additional oil. The challenge to develop new oil-recovery technology is restricted only by limits we set on our imagination. As investment in oil fields increases, improving recovery becomes more critical, and the search for the best solution becomes more difficult. Some solutions require entirely new concepts. Other solutions need only small adjustments or the use of an additional technique to overcome a challenge that precludes an otherwise successful project that uses an established EOR method.

Recommendation 6: International Act for Plugging and Abandoning must be followed and thoroughly implemented.

Recommendation 7: Monitoring of economic levels of oil and gas in wells should take place. The enhancement process needs to be applied before killing the well by emptying. The level at the instant of commencing the EOR may range from 30 up to 40 of the original level. The enhancement processes will at least double the production of wells within primary, secondary and territory phases.

Conclusion

Applying contingent plans to safeguard the environment, as well as to increase energy resources by applying either CO2 emission gases with or in the presence of mixture of fermented rubbish will reduce hazard waste contaminants. EOR can improve the cycles, the quality and the viscosity of the contained remaining residual oil or gas in the wells.

I have introduced this technique, called the IEOR Technique. It could be applied several times to have additions of the extracted produced oil and gas by several folds from the original quantity. The current suggested IEOR and IEGR, based on the fermentation process, will generate microbiological enhancement effects; and the presence of waste plastic bags and bottles can act as a catalyst like polymers. So this is the good way to reduce rubbish contamination and hazards that result in foul odors, the spreading of illnesses, etc. will all being reduced by controlling IEOR or IEGR. So the IEOR Technology will be the future dominated means for preventing reservoirs from getting the stage of being dry.

I believe that the IEOR and the IEGR both will witness large applications aiming at subsidizing the reservoir output production and will reduce emissions of CO2 and reduce the contamination of rubbish and waste. A clean, green and healthy environment with prosperous future societies will all be reflected in improving relationships between communities.

Moustafa Mohamed Gammal
Posted: 08/25/2010

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