Method and apparatus for production logging
Method and apparatus are disclosed for performing production logging in a cased well having a plurality of isolated production zones and a tubing string which intersects the production zones. An access device is connected in the tubing string for each of one or more production zones and an intervention tool is conveyed to and positioned in the access device associated with the selected production zone. Production parameters from the selected zone are measured by sensors in the intervention tool.
1. Field of the Invention
The present invention relates to method and apparatus for production logging in a cased, multilayer wellbore.
2. Description of the Prior Art
Well logging surveys are often made in producing oil and gas wells to determine the volumetric concentration of the oil, gas and unwanted water components in the production flow. These data along with measurements of the fluid flow velocity, pressure and temperature may be used to determine production rates and other information from each zone of interest in the well. Such data are essential for the improvement of oil and gas production, reducing water production, managing the field reservoir, and optimizing production from the well.
Obtaining reliable production information in deviated, multilayered, multi-phased reservoirs has proven to be a difficult task. This is due to segregation of the lower density phases, e.g. oil and gas, migrating to the high side of the hole where they cannot be adequately measured by centralized sensors. Such sensors may have a very limited circumferential area of measurement and may not read globally. Additionally, the heavier fluids, e.g. water, suffer from a phenomena known as “water fallback” where the heavier fluids falls back downhole, which may cause the velocity measurement to read an incorrect flow rate. Fluid segregation and fallback thus prevent all current technology from providing reliable production data in the majority of deviated wellbores.
Another shortcoming of current production logging technology is that it can only measure pressure in the borehole or production tubing and not the actual reservoir pressure of an individual layer in a multilayer reservoir. Capturing the actual reservoir pressure from the individual layer is critical to well optimization and proper understanding of reservoir support mechanisms, e.g. water floods.
If reliable production information concerning a reservoir can be obtained, decisions concerning the management of the reservoir should be enhanced. For example, with reliable production information from the production zones in a reservoir, informed decisions may be made concerning whether to continue to produce from a production zone, to close a production zone, or to treat a production zone, e.g. by fracturing. This affords an opportunity to respond to changes over time with the selection of production zones open to the production tubing. For example, production from hydrocarbon rich zones at relatively lower pressures may be delayed for the pressure to drop with the passage of time from production from higher pressure production zones. A failure to properly balance this may cause hydrocarbons brought out of one production zone to flow back into another zone at lower pressure, causing lost production and perhaps damage to the latter formation. Similarly, it can be useful to make other changes over time in managing individual production zones, the collective total, and the combined fluids produced based on the mixture of gas, water, and oil constituents, temperature, or other parameters observable from the fluid produced among each of several selected zones. Such informed decisions will tend to increase and perhaps even maximize production from the reservoir.
SUMMARY OF THE INVENTIONIn accordance with the present invention, a method of production logging in a cased well is provided. The cased well has a plurality of production zones that are isolated from one another and a tubing string for conveying production from said zones to the earth's surface. At least one access device is connected in the tubing string for each of one or more production zones, and each such access device has a port that allows production fluid to flow into the tubing string.
A method in accordance with the present invention comprises the steps of selecting one of the production zones from which to measure production parameters and then conveying an intervention tool to an access device associated with the selected production zone. A method in accordance with the present invention further comprises the step of positioning the intervention tool is in the selected access device so that the production fluid passes through the intervention tool. That step of positioning the intervention tool in the selected access device may comprise reducing the cross-sectional area through which production fluid from the selected production zone may flow. A method in accordance with the present invention further comprises measuring parameters associated with the production zone using sensors which are contained in the intervention tool.
The data that is generated by measuring the parameters of the production zone may be directly provided to a computer at the earth's surface. Alternatively, that data may first be stored in a memory device (which may be located downhole) and then provided to a computer. This computer may be programmed to use the data respecting the measured parameters to make decisions concerning future production from the well.
A method in accordance with the present invention comprises repeating the aforesaid steps for at least one more production zone in the well, and using the data respecting the measured parameters from the measured production zones to make decisions concerning the production from the well.
In accordance with the present invention apparatus is provided for use in production logging operations in a cased well having a plurality of production zones that are isolated from one another and a tubing string for conveying the production from the production zones to the earth's surface. Apparatus in accordance with the present invention comprises a plurality of access devices, which may be sliding sleeve devices and which are connected in the tubing string. At least one access device is connected in the tubing string for each of one or more production zones in the cased well. Apparatus in accordance with the present invention further comprises an intervention tool which is conveyed through the tubing string from the surface of the earth to a selected one of the access devices and is positioned in the access device that is associated with the selected production zone. One function that the intervention tool provides is to isolate the selected production zone from the other production zones. Once the intervention tool is positioned, the production flow from the isolated/selected production zone passes through the intervention tool, and the intervention tool contains sensors to measure parameters associated with the production zone corresponding to the access device in which the tubular member is positioned. The sensors may be selected from a group including those which measure pressure, density, temperature, capacitance/dielectric and velocity.
In accordance with the present invention, a production logging system is provided for use in a cased well having a plurality of production zones that are isolated from one another and a tubing string for conveying the production from said production zones to the earth's surface. The system comprises a plurality of access devices connected in the tubing string where there is at least one access device for each of one or more of said production zones. In one embodiment the access devices are sliding sleeve devices. A system according to the present invention comprises an intervention tool which is conveyed from the earth's surface to an access device associated with a selected production zone and which is positioned in that selected device. Parameters of the production zone corresponding to access device in which the intervention tool is positioned are measured with sensors in the intervention tool. A system in accordance with the present invention further comprises a computer which receives and processes the aforesaid data, and a recorder operatively connected to the computer for displaying information respecting said measured parameters.
In accordance with the present invention apparatus comprising an intervention tool is provided for use in production logging operations in a cased, completed well having a plurality of production zones that are isolated from one another, a tubing string for conveying the production from said production zones to the earth's surface, and one or more access devices connected in the tubing string where there is at least one access device for each of one or more of said production zones. An intervention tool in accordance with the present invention is for conveyance through the tubing string and is for positioning in the selected access device. An intervention tool according to the present invention comprises sensing devices to measure parameters of the production zone corresponding to the access device in which the intervention tool is positioned.
BRIEF DESCRIPTION OF THE DRAWINGS
It will be appreciated that the present invention may take many forms and embodiments. Some embodiments of the invention are described so as to give an understanding of the invention. It is intended for the embodiments of the present invention described herein to be illustrative, and not limiting, of the invention.
In accordance with the present invention, method and apparatus are provided for production logging in a cased, completed wellbore. With reference first of
The tubing string 18 comprises a plurality of tubular members, i.e. pipes, which are joined together in threaded engagement. A plurality of access devices 30 are joined in threaded engagement to tubular members in the tubing string 18. Each production zone 12, 14 and 16 has at least one access device 30 associated with it. While
The tubing string 18 connects to a wellhead 21 which is located at the earth's surface. The production fluids may be directed from the tubing string 18 via the wellhead to a pipeline (not shown). Wellhead 21 includes a port to permit access to the tubing string 18 by logging apparatus.
With reference now to
In the completed wellbore 100 of
In the completed wellbores shown in
In one embodiment, each access device 30 in
Referring now to
With reference to
With reference to
Dart 52 contains a plurality of sensors in its bore, which may, for example, include devices to measure pressure, density, temperature, capacitance/dielectric and/or velocity at the selected zone. In particular, the sensors may include: (a) in-line spinner 65 to measure velocity; and (b) fluid identification sensors, density sensors (nuclear or vibration method) and capacitance/dielectric sensors located at 63 between baffle plates 64. Baffle plates 64 are employed to force fluid into the fluid identification sensors to ensure accurate recording. The bore of dart 52 may also contain a sealing device 66 which may, for example, be a door 66 that is remotely controlled by a timer (not shown) that is powered by battery 69. When the sealing device 66 is closed as shown in
Dart 52 may also include ports 70 to allow fluid from below to enter the base of dart 52. In the event of a pressure differential between the fluid in the bore of dart 52 and the fluid below dart 52, there will be fluid movement toward equilibrium, and this fluid movement may be measured by spinner 67.
When it is desired to measure parameters of a selected production zone, the isolation tool 51 is conveyed through the tubing string 18 from the earth's surface to a sliding sleeve device 30 corresponding to the selected production zone by wireline, slickline, coiled tubing or other conveyance techniques. Preferably, such conveyance is carried out using conventional wireline techniques. The isolation tool 51 is positioned in the sliding sleeve device using the same techniques that are used to position a separation tool in a sliding sleeve device. The sliding sleeve device may be an “X” landing nipple profile and isolation tool 51 would therefore have locking keys 58 which match that nipple profile. Any nipple profile assembly or other “landing device” for cooperatively engaging a tool within the bore of another tool may, be used, so long as it is adequate to install the isolation tool 51. The ports 55 that were formed in tubular member 56 become fluidly coupled with and may be adjacent to the ports 44 in the sliding sleeve device 30 when the isolation tool 51 is positioned in the sliding sleeve. Once the isolation tool is positioned, the wireline is retrieved, and dart 52 is then lowered and is positioned within isolation tool 51, as illustrated in
In one embodiment of the present invention, the intervention procedure is thus a two “trip” process—one trip to position the isolation tool 51 in the sliding sleeve device and a second trip to position the dart 52 in the isolation tool 51. Similarly, the intervention tool in this embodiment comprises apparatus composed of two component pieces. Those skilled in the art, having the benefit of the present disclosure, will appreciate that the intervention procedure may be carried out in a single trip and that the isolation tool 51 and dart 52 may be formed as an integral piece of apparatus. The appended method claims are intended to cover multiple or single trip procedures to position the intervention tool and the appended apparatus/system claims are intended to cover an intervention tool which is formed as a single unit or in two or more component pieces.
With reference to
Referring to
By using the method and apparatus of the present invention, the well operator has more accurate and meaningful data concerning the production zone than has heretofore been available. In particular, the operator is able by using the present invention to measure actual reservoir pressure at each production zone of interest, which by itself should enhance well optimization endeavors. Without this information, production decisions may be based on more difficult to interpret data, for example, data in which information about an individual production zones may be interfered with by parameters such as the hydrostatic head and/or the net flowing pressure of other production zones.
Using the apparatus of the present invention, an operator has the ability to operate the apparatus in a long term memory mode in order to accumulate data over a preselected period of time, e.g. between one and thirty days. By accumulating information over such period of time, the operator is able to provide a more accurate information concerning the zone of interest. For example, as wells mature, water production generally increases which can cause the well to slug, and this effect is amplified with well deviation. The occurrence of the slug may, however, be difficult to predict. Therefore, by sampling the well over an extended period of time, it is believed that the effects of slugging can be averaged to provide a more consistent interpretation of results than are currently available.
Once measurements have been completed at one production zone, the intervention tool comprising the isolation tool 51 and dart 52 may me relocated to another production zone, and the above-described process may be repeated.
Claims
1. A method of production logging in a cased well having (i) a plurality of production zones that are isolated from one another, (ii) a tubing string for conveying production from said production zones to the earth's surface, and (iii) at least one access device connected in said tubing string for each of one or more production zones, each said access device having a port that allows production fluid to flow into in the tubing string, comprising the steps of:
- (a) conveying an intervention tool to an access device associated with a production zone from which production parameters are to be measured;
- (b) positioning said intervention tool in said access device so that production fluid passes through the intervention tool; and
- (c) measuring parameters of the selected production zone with sensors contained in said intervention tool.
2. The method of claim 1, further comprising the step of providing data respecting said measured parameters to a computer that is located at the earth's surface.
3. The method of claim 2, further comprising the step of using the data respecting the measured parameters to make decisions concerning production from the selected production zone.
4. The method of claim 2, further comprising the steps of repeating the steps of claim 2 for at least one more production zone in the well.
5. The method of claim 4, further comprising the step of using the data respecting the measured parameters from the measured production zones to make decisions concerning production from the well.
6. The method of claim 1, further comprising the step of storing data respecting said measured parameters in a memory device.
7. The method of claim 6, further comprising the step of providing the data stored in the memory device to a computer.
8. The method of claim 6, further comprising the steps of repeating the steps of claim 6 over a preselected period of time.
9. The method of claim 8, further comprising the step of providing the data stored in the memory device to a computer.
10. The method of claim 1, wherein step (b) comprises reducing the cross-sectional area through which production fluid from said production zone may flow.
11. A method of production logging in a cased well having (i) a plurality of production zones that are isolated from one another, (ii) a tubing string for conveying production from said production zones to the earth's surface, and (iii) at least one sliding sleeve device connected in said tubing string for each of one or more production zones, each said sliding sleeve having a port which permits production fluid to flow into the tubing string, comprising the steps of:
- (a) outfitting an intervention tool with one or more sensors to measure parameters;
- (b) conveying said intervention tool to a sliding sleeve device associated with a production zone from which production parameters are to be measured;
- (c) positioning the intervention tool in said sliding sleeve device so that the production fluid entering the port of said sliding sleeve device passes through the intervention tool; and
- (d) measuring parameters of the production zone with the sensors contained in the intervention tool.
12. The method of claim 11, further comprising the step of providing data respecting said measured parameters to a computer that is located at the earth's surface.
13. The method of claim 12, further comprising the step of using the data respecting the measured parameters to make decisions concerning production from the selected production zone.
14. The method of claim 12, further comprising the steps of repeating the steps of claim 11 for at least one more production zone in the well.
15. The method of claim 14, further comprising the step of using data respecting the measured parameters from the measured production zones to make decisions concerning production from the well.
16. The method of claim 11, further comprising the step of storing data respecting said measured parameters in a memory device.
17. The method of claim 16, further comprising the step of providing the data stored in the memory device to a computer.
18. The method of claim 16, further comprising the steps of repeating the steps of claim 15 over a preselected period of time.
19. The method of claim 18, further comprising providing the data stored in the memory device to a computer.
20. The method of claim 11, where step (c) comprises reducing the cross-sectional area through which production fluid from said production zone may flow.
21. Apparatus for use in production logging operations in a cased, completed well having a plurality of production zones that are isolated from one another and a tubing string for conveying the production from said production zones to the earth's surface, comprising:
- (a) a plurality of access devices connected in the tubing where there is at least one access device for each of one or more of said production zones; and
- (b) an intervention tool which: (i) is conveyed through the tubing string from the surface of the earth to a selected one of the access devices, (ii) is positioned in the selected access device, and (iii) contains sensing devices to measure parameters of the production zone corresponding to the access device in which the intervention tool is positioned.
22. The apparatus of claim 21, wherein the sensing devices are selected from a group of devices which measure pressure, density, temperature, capacitance/dielectric and/or velocity.
23. Apparatus for use in production logging operations in a cased, completed well having a plurality of production zones that are isolated from one another and a tubing string for conveying the production from said production zones to the earth's surface, comprising:
- (a) a plurality of sliding sleeve devices connected in the tubing string where there is at least one sliding sleeve device for each of one or more of said production zones; and
- (b) an intervention tool which: (i) is conveyed through the tubing string from the surface of the earth to a selected one of the sliding sleeve devices, (ii) is positioned in the selected sliding sleeve device, and (iii) contains sensing devices to measure parameters of the production zone corresponding to the sliding sleeve in which the intervention tool is positioned.
24. The apparatus of claim 23, wherein the sensing devices are selected from a group of devices which measure pressure, density, temperature, capacitance/dielectric and/or velocity.
25. A production logging system for use in a cased, completed well having a plurality of production zones that are isolated from one another and a tubing string for conveying the production from said production zones to the earth's surface, comprising:
- (a) a plurality of access devices connected in the tubing string where there is at least one access device for each of one or more of said production zones;
- (b) an intervention tool which: (i) is conveyed through the tubing string from the surface of the earth to a selected one of the access devices, (ii) is positioned in the selected access device, and (iii) contains sensing devices to measure parameters of the production zone corresponding to access device in which the intervention tool is positioned;
- (c) a computer which receives data respecting the measured parameters and processes that data; and
- (d) a recorder operatively coupled to the computer for displaying information respecting the measured parameters.
26. The system of claim 25, wherein the sensing devices are selected from a group of devices which measure pressure, density, temperature, capacitance/dielectric and/or velocity.
27. A production logging system for use in a cased, completed well having a plurality of production zones that are isolated from one another and a tubing string for conveying the production from said production zones to the earth's surface, comprising:
- (a) a plurality of sliding sleeve devices connected in the tubing string where there is at least one sliding sleeve device for each of one or more of said production zones;
- (b) an intervention tool which: (i) is conveyed through the tubing string from the surface of the earth to a selected one of the sliding sleeve devices via the tubing string, (ii) is positioned in the selected sliding sleeve device, and (iii) contains sensing devices to measure parameters of the production zone corresponding to the sliding sleeve in which the isolation tool is positioned;
- (c) a computer for receiving data respecting the measured parameters and for processing that data; and
- (d) a recorder operatively coupled to the computer for displaying information respecting the measured parameters.
28. The apparatus of claim 27, wherein the sensing devices are selected from a group of devices which measure pressure, density, temperature, capacitance/dielectric and/or velocity.
29. Apparatus for use in production logging operations in a cased, completed well having a plurality of production zones that are isolated from one another, a tubing string for conveying the production from said production zones to the earth's surface, and a plurality of access devices connected in the tubing string where there is at least one access device for each of one or more of said production zones, comprising:
- an intervention tool which (i) is for conveyance through the tubing string from the surface of the earth to a selected one of the access devices, (ii) is for positioning in the selected access device, and (iii) contains sensing devices to measure parameters of the production zone corresponding to the access device in which the intervention tool is positioned.
30. The apparatus of claim 29, wherein the access devices are sliding sleeve devices.
31. The apparatus of claim 29, wherein the sensing devices are selected from a group of device which measure pressure, density, temperature, capacitance/dielectric and/or velocity.
32. A method of production logging in a cased wellbore having a tubing string for conveying production fluid from the wellbore to the earth's surface, said tubing string including a landing device, comprising the steps of:
- outfitting an intervention tool with sensing devices;
- conveying the intervention tool to the landing device;
- cooperatively engaging the intervention tool with the landing device so that production fluid flows through the intervention tool; and
- measuring parameters of the production fluid with the sensing devices in the intervention tool.
33. The method of claim 32, further comprising the step of providing data respecting said measured parameters to a computer that is located at the earth's surface.
34. The method of claim 33, further comprising the step of using the data respecting the measured parameters to recommend decisions concerning production from the selected production zone.
35. The method of claim 33, further comprising the steps of repeating the steps of claim 31 for at least one more production zone in the well.
36. The method of claim 35, further comprising the step of using the data respecting the measured parameters from the measured production zones to recommend decisions concerning production from the well.
37. The method of claim 32, further comprising the step of storing data respecting said measured parameters in a memory device.
38. The method of claim 37, further comprising the step of providing the data stored in the memory device to a computer.
39. The method of claim 37, further comprising the steps of repeating the steps of claim 35 over a preselected period of time.
40. The method of claim 39, further comprising the step of providing the data stored in the memory device to a computer.
41. A method of production management for a hydrocarbon producing well having a plurality of potential production zones intersected by a wellbore, said method comprising:
- casing the wellbore;
- providing potential access through the casing to a plurality of said potential production zones;
- running a tubing string inside of the casing and in communication with the surface;
- isolating one or more of the potential production zones;
- providing one or more access devices each associated with one of the isolated potential production zones to allow selective fluid communication from said production zone into the tubing;
- engaging an intervention tool with one of said access devices;
- collecting data by measuring parameters of the isolated potential production zone associated with the engaged access device using sensors contained in said intervention tool; and
- making decisions for production management based on the data.
42. The method of claim 41, wherein data is collected at multiple production zones.
43. The method of claim 42, wherein the decisions for production management comprise leaving access devices open or shut, and treating an isolated section.
44. The method of claim 41, wherein the well is monitored over time and production from the well is optimized on an ongoing basis in response to changes in the well.
Type: Application
Filed: Sep 13, 2004
Publication Date: Mar 16, 2006
Inventors: Francis Heaney (Ardrossan), David Houdek (Ennis, TX)
Application Number: 10/939,749
International Classification: E21B 47/00 (20060101); E21B 43/12 (20060101);