One of the most pressing problems in the oil and gas industry is water flooding, which leads to significant, both economic and technical, costs. There are many options for solving this problem, they are cementing, drilling sidetracks, installing mechanical devices. These methods are labor-intensive and do not guarantee long-term isolation.
Types of water flow to a well:
- Through casing leakage;
- Through the non-hermetic cement ring into the existing perforation interval;
- Coning the bottom water;
- Through the breakthrough of injected water through the reservoir with maximum permeability.
To solve these problems, KazGeoTech LLP offers the use of IsoWell gelling agent.
IsoWell gelling agent provides selective isolation of water-saturated part of production horizon’s filtration channels. IsoWell includes a high-molecular polymer, a cross linker, a gelling inhibitor and water. While preparing IsoWell and pumping it into the reservoir, the inhibitor prevents gel formation by cross-linking polymer molecules into a spatial structure. The viscosity of the prepared composition is not significant and shall be determined by the polymer concentration. This ensures efficient pumping of the IsoWell gelling agent into the productive reservoir. When the composition gets into the water-saturated filtration channels, the inhibitor is sorbed on the reservoir rock. This creates a strong gel that effectively blocks the water-bearing portion of the reservoir.
IsoWell gelling agent is characterized by high permeability and by this characteristic is close to water, and the mass formed after gel formation in microchannels is mostly unmovable. To restore reservoir properties of the shelf, in case of incorrect pumping of the gelling agent or emergency situations, reagents capable of destroying gel in the pore space of reservoirs are selected.
In producing wells with high percentage of water flooding it is recommended to install gel screens, cutting off bottom waters. This method includes the special perforation in the zone of water-oil contact and creation of an extended water-proof screen separating water-saturated area from bottom water or water-bearing formation by pumping gelling agent through this interval. If necessary, perforation in the area of the reservoir top is performed and further operation of the producing well is carried out through a new perforation interval, created above the gel screen.
IsoWell gelling agent is easy and convenient to prepare, has adjustable time of gel formation, which eliminates emergency situations during injection into the reservoir, is capable of forming water and gas-insulating material in a wide range of reservoir temperatures and pressures