On the contrary of the polymer flood application consisting in viscosifying injection water, the principle of Water Shut-Off (WSO - production well treatment by polymers) is to solve production problems caused by early water breakthrough or reservoir fractures linked to water drive. The main purpose of WSO is thus to reduce water influx from the water producing zones in order to stimulate production from oil-bearing zones.
In a similar way, Conformance Control (CC- injection well treatment by polymers) consists in injecting polymer/gel formulations to solve water channeling problems in the reservoir (high-permeability streaks, reservoir fractures, etc.). Therefore, the main purpose of CC is to improve reservoir conformance by a deep treatment of the thief zones from the injection well. CC is also called “Profile Control”…
In the case below, a production well is represented producing from two layers: one low-permeability oil layer and one high-permeability water layer.
A broad range of chemicals called Powelgel™ was created to perform WSO and CC in most of the formations including those high salinity and high temperature. Some of these products may be used in North Sea.
Powelgel™ products descriptions :
Proven track records have been obtained in a wide variety of field situations (i.e. gas wells, water-flooded wells, heavy-oil horizontal wells, offshore gravel-pack wells…). The design of Poweltec WSO and CC’ treatments combines near-wellbore reservoir simulations and laboratory core-flood experiments.
Payout of WSO treatments is often achieved within 1 month. Plots of Cumulative oil vs. Cumulative water production enables a good evaluation of additional oil produced after the treatment.
An original polymer technology is proposed for the consolidation of poorly cemented sandstone formations. This technology is based on the adsorption of an "environmentally friendly" water-based polymeric film on pore walls, which can efficiently prevent the erosion of the cement of the rock under high flow rates. The treatment can be bullheaded into the whole open interval of the well, without specific tools for placement. The risk of well impairment is minimized by the use of RPM product. Remarkable results have been recently obtained in the treatment of gas wells and underground gas storage wells.
Poweltec can provide a full Polymer Flood design package from feasibility studies to design of large field pilots. Poweltec services include: