EOR Solutions
Water Shut-Off in Gas Wells

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Controlling and eliminating unwanted water influx into natural gas wells is a major concern of natural gas producers. Water influx can occur via several mechanisms (flow through fractures, channeling, or coning), and the water may approach from several directions (from below, from the sides, or from above).

Usually water is produced at the cost of gas recovery, and, in severe cases, the water influx becomes so great that the gas production is choked off completely. Polymer gel processes can prove quite effective in reducing water.

APPLICATION
The gel is injected into production wells at temperatures up to 300°F. It can solve the following problems:

Bottom Water Coning
Frac’ing Out of Zone
Natural Fractures
Connected to Bottom Water

DESCRIPTION
A gel placement technique that allows gel to be placed in water flow paths so that water is shut off without affecting gas. The technology involves gel and gas injection. The gel should be suitable for the temperature and salinity environment of the reservoir and flow path conductivity. For temperatures below 200°F and for higher temperatures, different TIORCO gels have been developed.

ADVANTAGES
Gel placement in water flow paths is high-graded, so water production is decreased without decreasing gas. This is important because without a proper placement strategy, gel may penetrate water and gas flow paths, shutting off both the unwanted fluid and the desired gas.

	Can be used in almost any type of mix water, but fresh water is best
	May not require zone isolation in fractured reservoirs
	Can place large volumes to block water flow paths further out from the wellbore than other methods. This reduces new flow paths bypassing the gel.
	Works up to 300°F. Can be formulated to work up to 350°F
	Payout is often within 6 to 9 months

CRITICAL DESIGN FACTORS
	Producers with high fluid levels are excellent candidates
	Wellbore must be clean so the gelant can be readily injected
	Minimum efficient injection rate and maximum injection pressure constrain treatment volumes
	Should be able to place over 50% of design gel volume without reaching pressure limit