Liquid gelling agent concentrates and methods of treating wells therewith

Abstract

The present invention provides liquid gelling agent concentrates and methods of treating wells therewith. A liquid gelling agent concentrate of this invention comprises an environmentally safe hydrocarbon carrier liquid, an organophillic clay suspending agent, a surfactant for dispersing the organophillic clay suspending agent in the carrier liquid and a particulate aqueous fluid gelling agent suspended in the carrier liquid.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to liquid gelling agent concentrates and methods of treating wells using the concentrates. [0003] 2. Description of the Prior Art [0004] Viscous gelled aqueous treating fluids are used in a variety of treatments in oil and gas wells including well completions and production stimulation treatments. An example of a well completion treatment which utilizes a viscous gelled aqueous fluid is known in the art as gravel packing. In gravel packing treatments, solid gravel particles such as sand are carried by way of the well bore to a subterranean zone in which a gravel pack is to be placed by a viscous gelled aqueous carrier fluid. That is, particulate solids (referred to in the art as gravel) are suspended in the viscous gelled aqueous carrier fluid at the surface and are carried to the subterranean zone in which the gravel pack is to be placed. Once the gravel is placed in the zone, the visc...

AI Technical Summary

Benefits of technology

[0009] The present invention provides storable liquid gelling agent concentrates that have improved storage, pour abilities and settling properties and methods of treating wells using the concentrates. A liquid gelling agent concentrate of this invention basically comprises an environmentally safe hydrocarbon carrier liquid, an organophillic clay suspending agent, a surfactant for dispersing the organophillic clay suspending agent in the hydrocarbon carrier liquid, and a particulate aqueous fluid gelling agent suspended in the carrier liquid.

[0011] The liquid gelling agent concentrate of this invention can be utilized in a variety of subterranean zone treatments such as fracturing subterranean zones, placing gravel packs in subterranean zones, and the like. The hydrocarbon carrier of the liquid gelling agent concentrate is an environmentally safe hydrocarbon liquid that meets the standards set forth in the Safe Drinking Water Act and does not include hazardous chemicals such as benzene, ethylbenzene, toluene or xylene. The hydrocarbon carrier liquid utilized in the liquid gelling agent concentrate can carry up to five pounds of gelling agent per gallon of the concentrate. The liquid gelling agent concentrate has a high flash point and a low pour point. In addition, the liquid gelling agent concentrate can be stored for long periods of time, has good pour abilities and settling properties and is easily combined with water to form a viscous gelled aqueous treating fluid.

Problems solved by technology

This procedure has very often resulted in undesirable agglomerations of the gelling agent in the polymer which are called “fish eyes.” Fish eyes are polymer masses wetted on the outside but with dry, unhydrated material inside.

While mechanical gelling agent feeders and adductors have been utilized to more efficiently wet the gelling agent, the feeders and adductors often fail to prevent the formation of fish eyes.

A problem with the liquid gelling agent concentrates utilized heretofore which include a hydrocarbon carrier fluid such as diesel oil is that the hydrocarbon carrier fluid contains compounds such as benzene, ethylbenzene, toluene, xylene and / or other compounds which are prohibited by the Environmental Protection Agency primary drinking water standards, i.e, Section 1429 of the Safe Drinking Water Act.

Another problem with such gelling agent concentrates is that they can not be stored for long periods of time and they often do not have good pour abilities or non-settling properties.