Liquid carbon dioxide cleaning of wellbores and near-wellbore areas using high precision stimulation
First Claim
1. A method for fracturing a fluid bearing formation having a wellbore comprising the steps of:
- introducing a quantity of fracturing fluid into said wellbore sufficient to fracture said formation;
introducing a treatment medium comprising liquid carbon dioxide into said wellbore; and
vaporizing at least a portion of said treatment medium;
wherein the steps of introducing a quantity of fracturing fluid into said wellbore and introducing a treatment medium comprising liquid carbon dioxide into said wellbore comprise the steps of;
regulating pressure within said wellbore and said formation such that at least a portion of said treatment medium remains in a liquid state following injection into said wellbore;
inserting a length of tubing into said wellbore such that an annulus is created between said tubing and said wellbore;
pumping said treatment medium through said tubing;
pumping said fracturing fluid into said annulus;
injecting said treatment medium into said fracturing fluid to create a second fluid;
impinging said second fluid against said formation;
creating at least one fracture in said formation;
driving said second fluid into said formation; and
releasing said pressure within said wellbore.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention relates to a method to clean a wellbore and the near wellbore area adjacent to the wellbore of a hydrocarbon bearing formation adjacent to the production zone of the wellbore. The invention includes a method to clean a casing inserted into a wellbore and a method for cleaning a wellbore of fracturing fluid, with or without proppant. Each of the methods includes the steps of injecting a treatment medium comprising liquid carbon dioxide into a wellbore where pressure within the wellbore is regulated to either maintain the treatment medium in the liquid state, or allow at least a portion of the treatment medium to vaporize upon introduction into the wellbore. The treatment medium vaporizes to loosen and/or entrain undesirable materials from within the wellbore or casing and escape through the wellhead, carrying with it the undesirable materials.
-
Citations
9 Claims
-
1. A method for fracturing a fluid bearing formation having a wellbore comprising the steps of:
-
introducing a quantity of fracturing fluid into said wellbore sufficient to fracture said formation; introducing a treatment medium comprising liquid carbon dioxide into said wellbore; and vaporizing at least a portion of said treatment medium; wherein the steps of introducing a quantity of fracturing fluid into said wellbore and introducing a treatment medium comprising liquid carbon dioxide into said wellbore comprise the steps of; regulating pressure within said wellbore and said formation such that at least a portion of said treatment medium remains in a liquid state following injection into said wellbore; inserting a length of tubing into said wellbore such that an annulus is created between said tubing and said wellbore; pumping said treatment medium through said tubing; pumping said fracturing fluid into said annulus; injecting said treatment medium into said fracturing fluid to create a second fluid; impinging said second fluid against said formation; creating at least one fracture in said formation; driving said second fluid into said formation; and releasing said pressure within said wellbore. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
Specification