COMBINATION INJECTION STRING AND DISTRIBUTED SENSING STRING FOR WELL EVALUATION AND TREATMENT CONTROL
A method for well intervention includes extending a combination conduit into a wellbore. The combination conduit includes a first conduit for moving fluid into the wellbore and a second conduit having at least one optical sensing fiber therein. A fluid is moved into the wellbore through the first conduit. A wellbore parameter is measured through a sensor associated with the at least one optical sensing fiber.
Priority is claimed from U.S. Provisional Application No. 61/047,925 filed on Apr. 25, 2008.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENTNot applicable.
BACKGROUND OF THE INVENTION1. Field of the Invention
The invention relates generally to the field of wellbore treatment using coiled tubing or similar intervention devices. More specifically, the invention relates to methods and devices for controlling injection of dewatering agents in gas wells to optimize production and to minimize wellbore shut in for retreatment.
2. Background Art
It is known in the art to inject chemicals such as foaming agents into wellbores that produce natural gas. The foaming agents combine with water that may be produced from one or more rock formations in the subsurface. The produced water can at least partially fill the wellbore. Hydrostatic pressure exerted by the column of produced water in the wellbore acts against natural gas entering the wellbore from one or more producing formations. Thus, hydrostatic pressure of water can reduce gas production. The foaming agent when introduced into the wellbore combines with the water and gas to reduce the density of the water by causing it to create foam. The reduced density foam results in a corresponding reduction in hydrostatic pressure against the gas producing formations, thus increasing gas production.
A common difficulty in using such chemical injection to improve gas well production is controlling the rate of injection of the foaming agent. Too little agent will result in insufficient reduction in the hydrostatic pressure of the water column. Too much agent can cause excessive foam lifting to the surface, which may require shutting the well in and cleaning the produced foam from production equipment at the surface.
It is known in the art to provide a distributed temperature sensor into a wellbore using a semi-rigid, spoolable intervention device. Such a device is sold under the trademark ZIPLOG, which is a trademark of Ziebel, A.S., Tananger, Norway, the assignee of the present invention. The ZIPLOG device is based on pushing a semi stiff spoolable rod into active, high deviation wells to perform distributed temperature sensing and single point in-wellbore pressure fluid surveys. Information about the Ziebel ZIPLOG system can be reviewed on the Internet at the Uniform Resource Locator http://www.ziebel.biz/newsletters/ZipLog%20Application%20Guide.pdf.
There exists a need for a system that can combine distributed sensing in a wellbore with fluid injection capability for real time monitoring of the effects of the intervention procedure.
SUMMARY OF THE INVENTIONA method for well intervention according to one aspect of the invention includes extending a combination conduit into a wellbore. The combination conduit includes a first conduit for moving fluid into the wellbore and a second conduit having at least one optical sensing fiber therein. A fluid is moved into the wellbore through the first conduit. A wellbore parameter is measured through a sensor associated with the at least one optical sensing fiber.
A wellbore intervention device according to another aspect of the invention includes a first conduit configured to move fluid therethrough. The device includes a second conduit including therein at least one optical fiber. The first conduit and the second conduit are enclosed in a spoolable encapsulant.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
In a method and system according to the invention, a distributed sensing system, such as a distributed fiber optic temperature sensor (“DTS”) may be inserted into a wellbore, such as a gas producing wellbore along with a fluid injection conduit in a single, spoolable system. The DTS may be of the same type as in the ZIPLOG system described in the Background section herein. For purposes of explaining the present invention, the DTS sensing elements, the pressure sensor and the surface equipment may be substantially the same as used in the ZIPLOG system.
In a system according to the invention, the DTS and fluid injection conduit may be combined into a single, semi-stiff, spoolable, combination conduit. An example of a combination conduit 10 is shown at a lower end thereof, as inserted into a wellbore, in
A cross section view of one example of the combination conduit 10 is shown in
Another example of a combination conduit is shown in cross section in
In using the combination conduit 10 shown in
When the conduit 10 is disposed to the selected depth in the wellbore, and referring to
It is then possible to remove the injector (32 in
During operation, measurements of pressure (using the sensor 20 in
Methods and systems according to the invention may enable more efficient production of gas from wellbores as well as more efficient use of foaming agents to assist in such gas production.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
Claims
1. A method for well intervention, comprising:
- extending a flexible, spoolable combination conduit into a wellbore, the combination conduit including a first conduit for moving fluid into the wellbore and a second conduit having at least one optical sensing fiber therein;
- moving a fluid into the wellbore through the first conduit; and
- measuring a wellbore parameter through a sensor associated with the at least one optical sensing fiber.
2. The method of claim 1 wherein the wellbore parameter comprises pressure.
3. The method of claim 1 wherein the wellbore parameter comprises temperature.
4. The method of claim 3 wherein the measuring temperature is performed at a plurality of positions along the wellbore.
5. The method of claim 1 wherein the wellbore parameter comprises a parameter related to fluid level in the wellbore.
6. The method of claim 1 wherein the fluid comprises foaming agent.
7. The method of claim 1 further comprising controlling a rate of movement of the fluid in response to measurements of the wellbore parameter.
8. A wellbore intervention device, comprising:
- a first conduit configured to move fluid therethrough;
- a second conduit including therein at least one optical fiber; and
- the first conduit and the second conduit enclosed in a spoolable, non-metallic encapsulant.
9. The device of claim 8 wherein the encapsulant comprises glass fiber reinforced plastic.
10. The device of claim 8 wherein the optical fiber comprises a distributed temperature sensing element.
11. The device of claim 8 wherein the first conduit and the second conduit are disposed in the encapsulant to thermally isolate the first conduit from the second conduit, and the second conduit is exposed to ambient temperature in the wellbore.
12. The device of claim 8 further comprising a fluid discharge control valve disposed at one end of first conduit.
13. The device of claim 8 further comprising a pressure sensor disposed at one end of the second conduit.
14. The device of claim 13 wherein the pressure sensor comprises an optical sensor.
15. The device of claim 13 further comprising a fluid pump coupled to the other end of the first conduit, and a control system in signal communication with the pressure sensor, the control system configured to operate the fluid pump such that a selected pressure is maintained in a wellbore when the intervention device is disposed in the wellbore.
16. The device of claim 8 wherein the first conduit and the second conduit comprise steel.
Type: Application
Filed: Apr 8, 2009
Publication Date: Oct 29, 2009
Inventors: Henning Hansen (Alicante), Charles R. Price (Conroe, TX)
Application Number: 12/420,071
International Classification: E21B 43/00 (20060101); E21B 43/16 (20060101); E21B 47/00 (20060101); E21B 47/06 (20060101); E21B 17/00 (20060101);