Wireless logging of fluid filled boreholes
A value of a property of a fluid-filled wellbore system can be detected. This can be accomplished by recording data including at least one of pressure and rate of flow at one or more locations in the wellbore system, and then estimating the value of the property by employing a model for predicting at least one of pressure and rate of flow dependent upon characteristics and locations of disturbances to pressure and flow in the wellbore system, in order to determine a best prediction of some attribute of the recorded data.
1. A method for estimating a value of a property of a liquid-filled wellbore system, comprising the steps of:
providing a receiver element for recording data including at least one of pressure and rate of flow at one or more locations in the liquid-filled wellbore system;
creating at least one acoustic disturbance in the liquid-filled wellbore system;
interpreting recorded data, wherein said recorded data includes a recording of the at least one acoustic disturbance in the liquid-filled wellbore system, to predict at least one attribute of the recorded data wherein said predicted attribute is a least one of amplitude, frequency, attenuation, dispersion, differential travel time, absolute travel time, and time resulting from the at least one acoustic disturbance; and
estimating the value of the property of the liquid filled wellbore system based on the predicted attribute of the recorded data, where the property includes one of pressure, pH, temperature, background radiation, location, fluid viscosity, density, velocity, electrical resistance or conductivity, compressive strength, shear strength attenuation and acoustic transmitivity.
2. The method of claim 1 in which the attribute of the recorded data includes the delay time of one or more peaks in the cross-correlation of the response from a sensor detecting at least one direct and at least one reflected disturbance.
3. The method of claim 1 wherein the at least one acoustic disturbance is created by changing pressure or flow.
4. The method of claim 1 wherein the at least one acoustic disturbance is created by changing state of one or more valves diverting flow from an input line.
5. The method of claim 1 wherein the at least one acoustic disturbance is created by changing state of one or more valves diverting flow into an output line.
6. The method of claim 1 including the further step of changing the viscoelastic properties of the liquid-filled wellbore system by changing state of one or more valves.
7. The method of claim 1 wherein the at least one disturbance are at a frequency in the range from DC to 40 kHz.
8. The method of claim 1 wherein pressure is recorded at a frequency between 0.01 Hz and 1 kHz.
9. The method of claim 1 wherein the at least one acoustic disturbance is created at a known time.
10. The method of claim 1 including the further step of employing at least one sensor in a supply portion of the system and at least one sensor in a return portion of the system.
11. The method of claim 10 in which the attribute of the recorded data is the delay time of one or more peaks in the cross-correlation of the response from a sensor in the supply portion of the system with the response from a sensor in the return portion of the system.
12. The method of claim 1 , wherein predicting the attribute of the recorded data comprises accounting for effects of parameters of the liquid-filled wellbore system.
13. The method of claim 12 wherein the parameters include a general representation of wellbore systems.
14. The method of claim 12 wherein the parameters include a representation specific to the fluid-filled wellbore system from which the value of the property is being estimated.
15. The method of claim 12 wherein the parameters detail at least one of wellbore system geometry, viscoelastic properties of the liquid-filled wellbore system, viscoacoustic properties of the fluid and entrained solids contained in the liquid-filled wellbore system, locations of boundaries and entrained solids.
16. The method of claim 1 wherein the at least one acoustic disturbance is created at a known location.
17. The method of claim 16 wherein the at leasat one acoustic disturbance is created at a known time.
18. The method of claim 16 wherein the at least one acoustic disturbance is created by arrival of an entrained solid at a known location.
19. The method of claim 18 including the further step of detecting arrival with a mechanical, fluidic or electronic sensor deployed as part of the fluid-filled wellbore system.
20. The method of claim 18 wherein the location is a casing float collar.
21. The method of claim 20 wherein the at least one acoustic disturbance is created due to rupture of an entrained solid or membrane.
22. The method of claim 21 wherein the entrained solid is a wiper plug.
23. Apparatus operable to estimate a value of a property of a liquid-filled wellbore system, comprising:
at least one sensor associated with a receiver element operable to record data including at least one of pressure and rate of flow at one or more locations in the liquid-filled wellbore system such that said recoded data is interpreted to predict at least one attribute of the recorded data wherein said predicted attribute is a least one of amplitude, frequency, attenuation, dispersion, differential travel time, absolute travel time, and time resulting from at least one acoustic disturbance within the liquid-filled wellbore system, and
an analyzer operable to estimate the value of the property of the liquid filled wellbore system based on the predicted attribute of the recorded data, where the property includes one of pressure, pH, temperature, background radiation, location, fluid viscosity, density, velocity, electrical resistance or conductivity, compressive strength, shear strength attenuation and acoustic transmitivity.
24. The apparatus of claim 23 wherein the attribute of the recorded data includes at least one of amplitude, frequency, attenuation, dispersion and travel time.
25. The apparatus of claim 23 wherein the attribute of the recorded data includes the delay time of one or more peaks in the cross-correlation of the response from a sensor detecting at least one direct and at least one reflected disturbance.
26. The apparatus of claim 23 further including a mechanism operable to create the at least one disturbance at a known time.
27. The apparatus of claim 23 further including a modulator operable to create the at least one disturbance by changing pumping pressure or flow.
28. The apparatus of claim 23 further including a modulator operable to create the at least one disturbance by changing state of one or more valves diverting flow from an input line.
29. The apparatus of claim 23 further including a modulator operable to create the at least one disturbance by changing state of one or more valves diverting flow into an output line.
30. The apparatus of claim 23 further including a modulator operable to change the viscoelastic properties of the liquid-filled wellbore system by changing state of one or more valves.
31. The apparatus of claim 23 wherein the at least one disturbance is at a frequency in the range from DC to 40 kHz.
32. The apparatus of claim 23 including at least one sensor in a supply portion of the system and at least one sensor in a return portion of the system.
33. The apparatus of claim 32 in which the attribute of the recorded data is the delay time of one or more peaks in the cross-correlation of the response from a sensor in the supply portion of the system with the response from a sensor in the return portion of the system.
34. The apparatus of claim 23 , wherein predicting the attribute of the recorded data comprises using a model to account for effects of parameters of the liquid-filled wellbore system.
35. The apparatus of claim 34 wherein the model includes parameters for pressure at a frequency between 0.01 Hz and 1 kHz.
36. The apparatus of claim 34 wherein the parameters detail at least one of wellbore system geometry, viscoelastic properties of the liquid-filled wellbore system, viscoacoustic properties of the fluid and entrained solids contained in the liquid-filled wellbore system, locations of boundaries and entrained solids.
37. The apparatus of claim 34 wherein the parameters include a general representation of wellbore systems.
38. The apparatus of claim 34 wherein the parameters include a representation specific to the liquid-filled wellbore system from which the value of the property is being estimated.
39. The apparatus of claim 23 further including a mechanism operable to create the at least one disturbance at a known location.
40. The apparatus of claim 39 wherein the mechanism is further operable to create the at least one disturbance at a known time.
41. The apparatus of claim 39 wherein the mechanism is further operable to trigger creation of the at least one disturbance in response to arrival of an entrained solid at a known location.
42. The apparatus of claim 41 further including a mechanical, fluidic or electronic sensor deployed as part of the liquid-filled wellbore system to detect arrival of the entrained solid.
43. The apparatus of claim 39 wherein the location is a casing float collar.
44. The apparatus of claim 43 wherein the at least one disturbance is generated by rupture of an entrained solid or membrane.
45. The apparatus of claim 44 wherein the entrained solid is a wiper plug.