By: RK Energy

When companies in the oil and gas industry need to keep a pipeline flowing, improve well production or neutralize corrosive substances, they use Enhanced Oil Recovery (EOR) technology such as water injection. Water injection systems are typically skid-mounted. In other words, the equipment is permanently mounted in a frame or onto a metal pallet during the manufacturing process. Skid-mounted equipment allows for easy, secure and safe transport as a unit to the field.

How It Works

Water injection involves drilling injection wells into a reservoir and adding water to stimulate oil production. The water helps to increase pressure within the reservoir which, in turn, helps to move the oil. An added bonus to this technology is the reduction in emissions. Water injection cools the combustion temperature which limits the level of Nitrogen Oxide that is released.

Water injection wells are drilled or production well can be converted into injection wells. Water is then pumped into the reservoir or gravity can help move the liquid along the pipeline.

Various sources of water are used for water injection. Filtration and processing of the water is sometimes required to avoid materials clogging the pipeline and to prevent bacteria growth. In order to reduce corrosion within the reservoir oxygen is also often removed from the water.

Increased Oil Recovery

Whether water injection occurs after oil has been depleted from the reservoir or before production has been drained, the injection of water pushes remaining oil to production wells where it can be recovered. Normally only 30% of the oil in a reservoir can be extracted, but with water injection anywhere from 5% to 50% of the remaining oil can be recovered, greatly enhancing the productivity and economics of the development.

Methods of Water Injection

There are a number of techniques for determining where water-injection wells should be drilled and what patterns they should be drilled in. Here are some of the most popular drilling techniques and patterns:

• The five-spot pattern includes drilling four water injection wells in a square shape around the production well. The pattern is repeated for each production well on the reservoir.
• The seven-spot pattern has six water-injection wells surrounding each production well. Again, this pattern is repeated around each production well on the reservoir.
• The inverted seven-spot pattern involves six production wells surrounding a single water injection well.
• Line patterns, rather than spot patterns, are often used. A direct line or staggered line of production wells is mimicked by a parallel line of water injection wells.
• Water injection wells are sometimes drilled along the outside border of the field and water is injected with fluid flowing toward the production wells in the center of the reservoir.
• Heated water can also be injected. This technique helps to make the oil more fluid especially in circumstances with heavy oil.

Quality Fabrication

RK Energy specializes in all oil field related products and services and is proud to be the National leader in the fabrication of water injected skidded equipment. The ease of maintenance is considered in the design of every building that RK Energy fabricates. Each water injection skid includes a simplex or duplex charge pump with low Net Positive Suction Head (NPSH) requirements, a filtering system, horizontal centrifugal water injection pumps, a flow transmitter and a flow metering valve. All parts are produced with stainless steel or coated carbon steel pipe. Water injection skids can also be built with enclosures for noise reduction and protection from the outdoor elements. Every enclosed building fabricated by RK Energy includes a North Dakota wiring certificate and is Colorado Resolution 35 compliant. Contact us at rkenergy@rkindustries.com for more information or a free consultation.