ABSTRACT
A new polymer has been introduced into the oilfield for use in hydraulic fracturing. Its unique properties complement the wide range of polymers currently in use. This biopolymer was originally developed for enhanced oil recovery and is now also used for gravel packing and as a mud Viscosifier.
The biopolymer causes minimal formation/proppant-pack permeability impairment - yielding the highest retained permeabilities of any polymer tested to date. It exhibits a constant viscosity up to a transition temperature (adjustable between 40°C and 100°C) beyond which the viscosity decreases to a level close to that of water. This eliminates the need for a breaker. The polymer is highly shear-thinning, resulting in the lowest tubing-head pressure of all fluids available. The good proppant-carrying capacity of the fluid is achieved without the addition of a crosslinker while fluid loss is similar to other polymers that are commonly used for fracturing.
The formulation of a fully functional fracturing fluid for use at medium temperatures without the need for a breaker or crosslinker is unique. In particular, it can be used with resin-coated proppants where unwanted side reactions occur with conventional fracturing fluids
The new fracturing fluid was successfully tested in combination with resin-coated proppant in the Southern North Sea.
