Water injection or water flooding refers to the typical secondary method where water is injected into the reservoir, usually to increase pressure and thereby stimulate production. Water is injected to support pressure in the reservoir and push oil to the producing wells. The bottom of the reservoir is filled with filtered water to push the oil towards the wells like a piston.
Normally only 30% of the oil in a reservoir can be extracted, but water injection increases that percentage (known as the recovery factor) and maintains the production rate of a reservoir over a longer period.
Water injection is used to compensate for low pressure in the reservoir. Water replaces the depleted oil, keeping production rate and the pressure constant over the long term. Depending on the viscosity of the oil, water flood is better than steam flood due to the cost to generate steam. Pricing and economics determine which method is most practical in an individual application.
The importance of proper water treatment is often underestimated by oil and engineering companies. If done incorrectly, water injection may not be successful and result in poor water quality, clogging the reservoir and loss of oil production. GTN and its team of prominent water flooding specialist ensures success by adhering to the strictest standards of water flooding management.
A global comprehensive study of viscous crude oil production under the banner of the Society of Petroleum Engineers shows that water flooding without heat under certain conditions is the best and most inexpensive method to achieve high recovery rates for viscous oil, particularly when the oil is non-paraffinic.
The 2008 study Water flooding Viscous Oil Reservoirs published by Dennis Beliveau illustrates that viscous oilfields yield good water flood recoveries when a few basic principles are closely followed. Mr. Beliveau is our advisor on GTN Energy Partners projects.
While a good correlation exists between recovery rates and volume of water injection, other factors such as well spacing and viscosity impact the success of water flood recovery. Additionally, reservoir characteristics of porosity and permeability, appropriate facility design, a voidage replacement ratio close to unity, flexibility in adjusting the water flood patterns employed and the proper reservoir surveillance are all the keys to successful and economic projects. Mr. Beliveau's study is available in the Data Room on GTN’s Website.
As quoted from the study, “...water flooding is sometimes dismissed as an ineffective process for a viscous oilfield, with the development plans focused on more exotic and expensive recovery mechanisms such as chemical or thermal process. However, basic application of Darcy’s law and fractional flow theory, combined with operations that focus on production at very high water cuts, clearly shows that viscous oilfields can yield reasonably good ultimate recoveries under water flood.”
The study gathers data from fifteen viscous oil field in Alberta, Canada, thirteen from Saskatchewan, three from the USA, one from the Netherlands , one from India and four from China.
The reservoir characteristics at Massie West Ranch and at Schenkel are substantially better than the vast majority of reservoirs in other parts of the world that have a track record of water flooding successes.
The GTN non-paraffinic reservoirs combine an acceptable API of 18 and a viscosity in-situ of 175cP with exceptional porosity of 1.2 Darcy and permeability
of 30% in order to achieve above standards mobility that is highly compatible with water flooding.
These parameters are in line with Mr. Beliveau’s conclusions, and while his study do not account for porosity and permeability, our exceptional reservoir characteristics substantially contribute to our recovery ratio.
The importance of proper water treatment is often underestimated by oil companies and engineering companies. If not addressed correctly, water injection may not be successful. This results in poor water quality, clogging of the reservoir and loss of oil production. This is not the case with GTN Energy Partners.
GTN has the expertise of Mr. Clem who has a history working with water. In 2011 the drought and environmental issues plagued the country. Express Energy Services, LP invited Mr. Clem to assist in the development and implementation of a water management division. He was responsible for establishing a new water management service line for the United States.
This was during the developmental stage which included final R&D of a Thermal Desalination Unit that can process high brine produced water and turn it into pure distilled water. Mr. Clem was able to bring the Thermal Desalination Unit to commercial viability on the designated time and under budget.
The use of water flooding can still become costly if it requires large amounts of water to extract the oil. In our case we have our own substantial water supply running beneath the surface of the property. This takes out a middle man. Although there is some cost toward the mineral owner it is much less than paying for outside water and the cost of transportation.
For more information: http://petrowiki.org/Waterflooding
- "New Billions In Oil" Popular Mechanics, March 1933—i.e. article on invention of water injection for oil recovery.
- Abdus Satter, Ghulam M. Iqbal, and James L. Buchwalter, Practical Enhanced Reservoir Engineering (Tulsa, Okla.: Pennwell, 2008) 492