METHOD FOR SEALING WELLBORE LEAKAGE AND SHUTTING-OFF OF WATER PRODUCING ZONES
A method for sealing a wellbore includes moving a running tool with a sealing material disposed therein into a wellbore proximate a portion of the wellbore to be sealed. A cylinder is moved into the wellbore along with the running tool proximate to the portion to be sealed. The cylinder defines an annular space between an exterior thereof and an interior of the wellbore. The sealing material is deployed into the annular space. The running tool is then removed from the wellbore.
Priority is claimed from U.S. Provisional Application No. 61/021,722 filed on Jan. 17, 2008.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTNot Applicable
BACKGROUND OF THE INVENTION1. Field of the Invention
The invention is related generally to the field of wellbore construction and repair. More particularly the invention is related methods and devices for selectively repairing leaks or hydraulically closing perforations in strings of pipe disposed in a wellbore drilled through subsurface rock formations.
2. Related Art
Wellbores drilled through subsurface rock formations typically include one or more lengths of pipe (“strings”) disposed therein. The pipe may be cemented into the open, drilled wellbore (called a “casing” if extending to the surface or a “liner” if extending only part way of the wellbore) to hydraulically isolate the subsurface formations and to protect the mechanical integrity of the wellbore. Another pipe string may be coaxially inserted into a casing in the wellbore to increase fluid velocity along the wellbore (such string called production or injection “tubing” depending on fluid direction of movement) as fluid is withdrawn from a subsurface reservoir or is injected into a reservoir.
In certain cases, casings or tubings can develop leaks. Such leakage may be caused by corrosion resulting in holes in the pipe, by threaded couplings on the pipe not being properly assembled (“torqued up”) during wellbore installation, among other causes of leaks.
It is also known in the art that part of a wellbore drilled through a subsurface reservoir needs to be hydraulically closed (“shut off”) when the fluids entering the wellbore from certain parts of a reservoir are not the fluids intended to be produced to the Earth's surface, as for example, water. Such undesired fluid entry can occur, for example, in the later stage of production from a reservoir, for example due to wrongly placed perforations and water coning, among other reasons.
The present invention relates to sealing wellbore sections that have such unwanted leakage or unwanted fluid production. In some examples, the method uses an induction-heating tool such as one described in U.S. Pat. No. 7,036,593, entitled Cement heating tool for oil and gas well completion, and issued to Thomas A. Larovere. Another such tool is described in Canadian Patent No. 2,592,556 entitled, Method and apparatus for plugging perforations, invented by Homer L. Spencer.
SUMMARY OF THE INVENTIONA method for sealing a wellbore according to one aspect of the invention includes moving a running tool with a sealing material disposed therein into a wellbore proximate a portion of the wellbore to be sealed. A cylinder is moved into the wellbore along with the running tool proximate to the portion to be sealed. The cylinder defines an annular space between an exterior thereof and an interior of the wellbore. The sealing material is deployed into the annular space. The running tool is then removed from the wellbore.
A method for sealing a wellbore according to another aspect of the invention includes moving an induction heating device with a thermally actuated sealing compound into a wellbore proximate a portion of the wellbore to be sealed. An annular cylinder is moved into the wellbore along with the induction heating device. The induction heating device is activated until the compound is actuated. The fused compound is moved into an annular space between the cylinder and the wellbore. The heating device is then withdrawn from the wellbore.
The invention described herein is based on using a device such as induction heating tool in combination with a device that enables a cylindrical, hollow plug to be placed and sealingly engaged in a wellbore.
Also, the invention described herein can be used for placing plugging materials by other tools, where plugging material can be epoxy, rubber-type compound, resins or other similar suitable fusible materials.
Other aspects of the invention will be apparent from the description and claims that follow.
As soon as the compound (8) has solidified or fully cured, a pressure test can be performed to ensure proper sealing in the casing (1) or tubing (2). Thereafter, the induction-heating tool (4A) can be released from the cylinder (9) and retrieved to the surface.
The cylinder (9), as well as the sealing system (10) and the centralizer (7) can be manufactured from materials susceptible to easy removal from the wellbore. One example is a composite material such as glass fiber or carbon fiber reinforced plastic. Another example metal such as aluminum. Aluminum has the advantages of higher strength that composites, and can be dissolved after a short time in a wellbore having suitable caustic agents, thus causing the annular cylinder shaped sealing plug created by the sealing compound (8) to have a larger internal pass through diameter. If the cylinder (9), sealing device (10) and the centralizer (7) are made from composite material, the foregoing devices may be removed from the casing or tubing by milling or grinding, using a mill or grinding device that will not damage the casing or tubing.
The same method of repair plug placement can be used without the heating tool (4A). In such examples, other types of sealing compounds that do not require heating for activation may be used, such as such as chemically activated resins, chemically activated rubber generating compounds, epoxy, and the like. In such examples, the sealing material may be transported to the running tool from the surface either through a casing or tubing inserted into the well, or by an intervention pipe deployed in the well, such as coiled tubing or small diameter threadedly coupled tubing.
While the invention has been described in terms of a limited number of specific examples, those skilled in the art, having the benefit of the present disclosure will readily devise other implementations which do not depart from the scope of what has been invented. Accordingly, the invention shall be limited in scope only by the following claims.
Claims
1. A method for sealing a wellbore, comprising:
- moving a running tool with a sealing material disposed therein into a wellbore proximate a portion of the wellbore to be sealed;
- moving a cylinder into the wellbore along with the running tool proximate to the portion, the cylinder defining an annular space between an exterior thereof and an interior of the wellbore;
- deploying the sealing material into the annular space; and
- removing the running tool from the wellbore.
2. The method of claim 1 further comprising removing the cylinder from the wellbore.
3. The method of claim 2 wherein the removing the cylinder comprises dissolving the cylinder.
4. The method of claim 1 the sealing material is activated prior to deployment.
4. The method of claim 1 wherein the activating comprises thermal fusing.
5. The method of claim 1 wherein the activating comprises thermochemical activation.
6. The method of claim 1 wherein the activating comprises chemical activation.
7. The method of claim 1 wherein the sealing material is pumped in from surface through at least one of one of a tubular in the wellbore to be sealed and through an intervention tubing inserted into the wellbore.
Type: Application
Filed: Jan 14, 2009
Publication Date: Jul 23, 2009
Inventor: Henning Hansen (Alicante)
Application Number: 12/353,272
International Classification: E21B 33/13 (20060101); E21B 33/12 (20060101); E21B 29/00 (20060101);