1. Field of the Disclosure
This disclosure relates generally to oil and gas well logging tools. More particularly, this disclosure relates to tools and methods for identifying the influx of gas into the borehole in real-time during drilling operations.
2. Description of the Related Art
Exploration for hydrocarbons commonly includes using a bottomhole assembly including a drill-bit for drilling a borehole in an earth formation. Drilling fluid or “mud” used in the drilling may vary in density or “mud weight” for a number of reasons. Such variations can result from changes in the quantity and density of cuttings (particles of formation); changes in the “mud program” at the surface, changes in temperature, etc. Variations in mud density also occur when gas or liquid enter the borehole from the formation. Such influx of formation fluids may likely be the result of formation overpressures or abnormally high pressures.
Pressure detection concepts are especially important in drilling. Not only does the drilling rate decrease with a high overbalance of mud pressure versus formation pressure, but also lost circulation and differential pressure sticking of the drill pipe can readily occur. More importantly, an underbalance of mud pressure versus formation pressure can cause a pressure “kick.” A well may kick without forewarning. Balanced drilling techniques often require only a fine margin between effective pressure control and a threatened blowout. Additionally, there are situations where underbalance is maintained to avoid formation damage so that it is important to detect inflow of formation liquids into the borehole.
Some prior art techniques for detecting abnormal formation pressure are based on measurement of drilling parameters such as drilling rate, torque and drag; drilling mud parameters such as mud gas cuttings, flow line mud weight, pressure kicks, flow line temperature, pit level and pit volume, mud flow rate; shale cutting parameters such as bulk density, shale factor, volume and size of cuttings. A drawback of some of these measurements is that they are not available in real-time but one must wait for the bottom hole fluid to reach the surface.
Other prior art methods for identifying possible kicks rely on density measurements of the borehole fluid. See, for example, U.S. Pat. No. 4,492,865 to Murphy et al., U.S. Pat. No. 4,412,130 to Winters, U.S. Pat. No. 6,648,083 to Evans et al., and U.S. Pat. No. 6,768,106 to Gzara et al. A drawback of methods that make density measurements is that gas must be present in sufficient quantities to affect the density of the mud, so that dissolved gas that may be a precursor to a gas kick would not register with conventional density measuring devices. In addition, the density measurements made by the prior art devices are responsive to varying degrees to the density of the formation. They also require the use of a radioactive source—a safety hazard during drilling operations.
There is a need for a technique to measure the properties of the borehole fluid downhole with a single tool in order to detect kicks and inflow of formation liquids. The present disclosure satisfies this need.
In one aspect, the present disclosure provides a method of detecting a gas influx event in a borehole fluid during drilling operations that includes: obtaining a measurement of an acoustic velocity of the borehole fluid at an acoustic sensor disposed in a borehole; obtaining a measurement of temperature of the borehole fluid at a temperature sensor disposed in the borehole; and comparing the measurement of the acoustic velocity of the borehole fluid to the measurement of the temperature of the borehole fluid to detect the gas influx event.
In another aspect, the present disclosure provides an apparatus for detecting a gas influx event in a borehole fluid during drilling operation that includes: an acoustic sensor configured to obtain a measurement of an acoustic velocity of the borehole fluid; a temperature measuring device configured to obtain a measurement of a temperature of the borehole fluid; and a processor configured to compare the measurement of the acoustic velocity of the borehole fluid to the measurement of the temperature of the borehole fluid to determine a gas influx event.
In yet another aspect, the present disclosure provides a computer-readable medium having a set of instruction stored thereon that when read by a processor enable the processor to perform a method, the method including: receiving a measurement of an acoustic velocity of a borehole fluid from an acoustic sensor disposed in a borehole; receiving a measurement of temperature of the borehole fluid from a temperature sensor disposed in the borehole; and comparing the measurement of the acoustic velocity of the borehole fluid to the measurement of the temperature of the borehole fluid to detect a gas influx event.
Examples of certain features of the apparatus and method disclosed herein are summarized rather broadly in order that the detailed description thereof that follows may be better understood. There are, of course, additional features of the apparatus and method disclosed hereinafter that will form the subject of the claims.
The present disclosure is best understood with reference to the accompanying figures in which like numerals refer to like elements and in which:
During drilling operations, a suitable drilling fluid 31 from a mud pit (source) 32 is circulated under pressure through a channel in the drillstring 20 by a mud pump 34. The drilling fluid passes from the mud pump 34 into the drillstring 20 via a desurger (not shown), fluid line 38 and Kelly joint 21. The drilling fluid 31 is discharged at the borehole bottom 51 through an opening in the drill bit 50. The drilling fluid 31 circulates uphole through the annular space 27 between the drillstring 20 and the borehole 26 and returns to the mud pit 32 via a return line 35. The drilling fluid acts to lubricate the drill bit 50 and to carry borehole cutting or chips away from the drill bit 50. A sensor S1 typically placed in the line 38 provides information about the fluid flow rate. A surface torque sensor S2 and a sensor S3 associated with the drillstring 20 respectively provide information about the torque and rotational speed of the drillstring. Additionally, a sensor (not shown) associated with line 29 is used to provide the hook load of the drillstring 20.
In one embodiment of the disclosure, the drill bit 50 is rotated by only rotating the drill pipe 22. In another embodiment of the disclosure, a downhole motor 55 (mud motor) is disposed in the drilling assembly 90 to rotate the drill bit 50 and the drill pipe 22 is rotated usually to supplement the rotational power, if required, and to effect changes in the drilling direction.
In an exemplary embodiment of
In one embodiment of the disclosure, a drilling sensor module 59 is placed near the drill bit 50. The drilling sensor module contains sensors, circuitry and processing software and algorithms relating to the dynamic drilling parameters. Such parameters typically include bit bounce, stick-slip of the drilling assembly, backward rotation, torque, shocks, borehole and annulus pressure, acceleration measurements and other measurements of the drill bit condition. A suitable telemetry or communication sub 72 using, for example, two-way telemetry, is also provided as illustrated in the drilling assembly 90. The drilling sensor module processes the sensor information and transmits it to the surface control unit 40 via the telemetry system 72.
The communication sub 72, a power unit 78 and an MWD tool 79 are all connected in tandem with the drillstring 20. Flex subs, for example, are used in connecting the MWD tool 79 in the drilling assembly 90. Such subs and tools form the bottom hole drilling assembly 90 between the drillstring 20 and the drill bit 50. The drilling assembly 90 makes various measurements including the pulsed nuclear magnetic resonance measurements while the borehole 26 is being drilled. The communication sub 72 obtains the signals and measurements and transfers the signals, using two-way telemetry, for example, to be processed on the surface. Alternatively, the signals can be processed using a downhole processor in the drilling assembly 90.
The surface control unit or processor 40 also receives signals from other downhole sensors and devices and signals from sensors S1-S3 and other sensors used in the system 10 and processes such signals according to programmed instructions provided to the surface control unit 40. The surface control unit 40 displays desired drilling parameters and other information on a display/monitor 42 utilized by an operator to control the drilling operations. The surface control unit 40 typically includes a computer or a microprocessor-based processing system, memory for storing programs or models and data, a recorder for recording data, and other peripherals. The control unit 40 is typically adapted to activate alarms 44 when certain unsafe or undesirable operating conditions occur.
Turning now to
As shown in
As shown in
The present disclosure relies on the signals recorded by excitation of the transducer as an indication of gas in the borehole fluid. Free gas in the borehole fluid has three main effects on the acoustic properties of the fluid. The first effect is a reduction in density of the fluid. A more important effect is the dramatic reduction in the bulk modulus of the fluid (and hence the acoustic velocity). This is the phenomenon that is the basis for the so-called “bright spot” effect in hydrocarbon exploration wherein the presence of gas in a reservoir can produce strong reflections on seismic data. Basically, in a gas-liquid mixture, the average compressibility (the reciprocal of bulk modulus which is linearly related to the square of the acoustic velocity) is obtained by a weighted average of the compressibilities of the two fluids. The third effect that may be observed is the attenuation of the wave that actually propagates into the borehole and may be reflected by the borehole wall. However, by the time actual gas bubbles appear in the borehole at depth, it may be on the verge of a blowout. Accordingly, an objective of the disclosure is to determine the pressure kicks before gas comes out of solution in the borehole fluid.
Invasion of formation fluids into the borehole is usually the result of the formation pore pressure exceeding the fluid pressure in the borehole. This may be a harbinger of a blowout and remedial action is necessary. Due to the difference in the density and P-wave velocity of the borehole mud and the density and P-wave velocity of formation fluid, this influx is detectable. Specifically, the effect of invasion is to lower the bulk modulus and density of the fluid in the borehole. This translates into a change in the impedance (and the velocity) of the mud.
Such a model may also be used for predicting the properties of a mixture of drilling mud and formation fluid. The net result of a fluid influx is to change the impedance of the borehole fluid.
Those versed in the art and having benefit of the present disclosure would recognize that if the impedance of the fluid is close to that of the plate, then reverberations of the plate caused by excitation of the transducer will decay very rapidly. This is shown schematically in
Maximum sensitivity is obtained by using a plate whose acoustic impedance is as close as possible to the fluid impedance so as to minimize the impedance contrast with the fluid, which typically ranges from 1500 kRayls for a light drilling fluid to 2300 kRayls for a heavy drilling fluid. The plate must also be thermally stable, mechanically tough, and chemically resistant. Among polymers, a polyimide ranging from 2400 to 2920 kRayls or a poly(etherether-ketone) ranging from 3122 to 3514 kRayls are good candidates. Another polymer that is a good candidate is polymethlypentene (tradenamed TPX, which is made by Mitsui) that has an acoustic impedance of 1840 kRayls. Pyrolytic graphite (6 480 kRayls depending on orientation) from GE Advanced Ceramics is a good candidate. Among metals, titanium (about 24 000 kRayls) or aluminum (about 15 800 kRayls) are good candidates. The inside face of the plate is in contact with oil in a pressure-balanced enclosure, with known acoustic characteristics. Incoming water oil or gas is expected to lower the acoustic impedance markedly. The instrument takes a reading every second and stores it in memory for 2 hours. In one embodiment of the disclosure, if the instrument observes a change in acoustic impedance of 10% or more during a 2 minute interval from the extrapolated value of the preceding hour then it sends a high priority alarm and a series of informative values of the acoustic impedance from say intervals of 20 seconds preceding the alarm. The use of a 10% change in acoustic impedance is for exemplary purposes only and other criteria could be used for sending an alarm.
Another embodiment of the disclosure is illustrated in
The discussion above has focused on one effect of gas influx on borehole fluid properties, namely, fluid impedance. However, as noted above, the velocity of compressional waves in the borehole fluid is also affected by gas influx. U.S. patent application Ser. No. 11/194,365 of DiFoggio, having the same assignee as the present disclosure and the contents of which are incorporated herein by reference, discloses a method of estimating a fluid property with a sampling vessel using an estimated velocity of an acoustic signal. The principles disclosed therein are also applicable for MWD applications.
Before discussing this embodiment, it is worthwhile to point out differences between oil-based mud and water-based mud insofar as the effect of gas influx is concerned. Water based muds can only accommodate approximately 50 cubic feet of dissolved gas per barrel of mud whereas the oil based muds can accommodate many times more dissolved gas. If only dissolved gas is present (but no free gas, which means no bubbles), sound speed will drop faster in water based mud than in oil based mud with increasing gas concentration (
In contrast,
DiFoggio discloses an arrangement for measuring fluid velocities in a sample chamber on a BHA or a wireline assembly. In the present disclosure, instead of using a sample chamber, a transducer assembly is positioned on the outside of the drill collar. This is illustrated in
The acoustic sensor assembly 803 is shown in more detail in
v=2d/Δt
There are prior art teachings of using travel time measurements over two different distances to estimate the fluid velocity. These suffer from the drawback that two different source pulses are involved, either from two different transducers or from the same transducer at two different times. The two different source pulses inevitably have somewhat different waveforms, so that estimating a difference of the travel times to extremely high precision is limited by the differences between those two source waveforms. This is particularly true in the present case where the acoustic pulses are transmitted through an attenuative and dispersive medium, namely, the borehole fluid. With the present transducer, the problem of source waveform variability is eliminated because the arrivals at the two different times, which are being compared, are both echoes of the very same generated acoustic pulse. There are several waves to estimate the travel time difference Δt.
In one embodiment of the disclosure, an autocorrelation of the received signal is performed and a peak value of the autocorrelation gives the travel time. Alternatively, a cross-correlation of two different windows of the received signal is used, the two different windows being selected based on an expected arrival time for the acoustic pulse in order to avoid spurious aliasing. The more closely spaced the time channels for collecting the received signal, the better that the travel time resolution will be. To obtain sub-channel resolution, we interpolated the peak position between time channels. The conceptual basis for sub-channel resolution is to fit a polynomial to the autocorrelation function in the neighborhood of the peak and then to find the zero crossing (the root) of the first derivative of that polynomial, which is the interpolated peak position. Because the time channels were uniformly spaced, we were able to use the computationally-simple Savitzky Golay method to compute the first derivative, f′, of the fitting polynomial at two time steps (the one just left and the one just right of the peak), and then to perform linear interpolation of the first derivative to obtain its zero crossing, which is the interpolated peak position, xP. That is, f′(xL)/[−f′(xR)]=dL/dR, where dL=xP−xL and dR=xR−xP and dL+dR=xR−xL. Of course, quadratic interpolation or iterative root finding could also have been used to find xP. Using such correlation and sub-channel interpolation methods, the transducer structure of
Such a precision may be hard to achieve in a borehole environment due to the attenuative and dispersive nature of the signals in mud. There are two main causes for this dispersion and attenuation. The first is due to the presence of solid particles in the mud that absorb acoustic signals. A second cause of dispersion and attenuation is the presence of gas bubbles. Elastic theory predicts that as long as concentration of gas bubbles is low and the gas bubbles are much smaller than a quarter of the wavelength of the acoustic pulses, the reflections of the acoustic pulse would still be detectable. As the concentration of gas bubbles increases and their size increases, no reflected signals would be detectable.
For the situation where there is a detectable reflection, the estimate of the travel time can be improved using deconvolution methods. Specifically, in one embodiment of the disclosure, a Wiener deconvolution of the second arrival of the received signal is performed using, as a reference wavelet, the first arrival. See Honvarvar et al. (2008).
In another embodiment of the disclosure, a travel time is measured for the reflection from the protruding portion of the reflector. This may be done if the reflection from the recessed portion is too weak. In such a case, the distance between the transmitter and the protruding portion of the reflector is used. A single reflection may also be used with a transducer assembly that has a flat reflector. In such situations, the estimate of the travel time may be improved using the method disclosed in DiFoggio. Specifically, the raw amplitude data can be first processed by applying a digital bandpass filter to reject any frequencies that are not close to the acoustic source frequency. For example, for a 10 MHz acoustic source and a 40 MHz sampling frequency, one could apply a 9-11 MHz digital bandpass filter. Next, one can compute the square of the amplitude at each sampling time, which corresponds to the energy received at that time. Then, one can generate a cumulative sum of squares (CSS) of these amplitudes, which is the cumulative sum of energy received up until that time. The digital bandpass filtering and cumulative sum of squares have already smoothed the raw data and removed some noise. We can further smooth the filtered cumulative sum of squares data and also take the first and second derivatives of the CSS using the Savitzky-Golay method (Savitzky and Golay, Analytical Chemistry, Vol. 36, No. 8, July 1964). The first derivative of CCS generates a series of Gaussian-looking peaks. The second derivative of the CSS are the first derivatives of the Gaussian peaks, whose zero crossings (roots) represent the interpolated peak positions. Smoothing the data and the utilization of the Savitzky-Golay method helps to reduce noise from the desired signal.
Returning now to the issue of direct measurement of impedance, another embodiment of the disclosure makes direct measurements without relying on measuring the resonance of a sensor plate.
of the parallel RLC load circuit 1165, giving the impedance of the mud Rv.
Turning to
Based on the discussions above, it can be seen that detection of gas influx is relatively easy to do when oil-based-mud (OBM) is used. Pulse transmission techniques may be used, and generally give a more precise estimate of gas saturation than do impedance measurements. Above the bubble point, pulse transmission techniques have some difficulty in getting measurable signals. When water-based-mud (WMB) is used, due to the low solubility of gas in water, it becomes more difficult for pulse transmission techniques to accurately measure saturation, particularly as the gas saturation and/or bubble size increases. Impedance measurements, while less precise, can give estimates of gas saturation above bubble point. With either method, it is important to monitor the gas saturation during drilling operations. When no detectable reflection, or a severely attenuated reflection is received by the transducer, this is referred to as a null output and the processor indicates the presence of bubbles in the fluid. The margin of safety is somewhat larger for OBM.
The presence of gas from a gas influx event causes a change in an acoustic velocity of the borehole fluid as well as a change in a temperature of the borehole fluid. Thus, a measured change in a temperature of the borehole fluid may be used to confirm a gas influx event that is detected using a measured change in the acoustic velocity of the borehole fluid.
The processing of the data may be accomplished by a downhole processor and/or a processor at the surface. Alternatively, measurements may be stored on a suitable memory device and processed upon retrieval of the memory device for detailed analysis. Implicit in the control and processing of the data is the use of a computer program on a suitable machine readable medium that enables the processor to perform the control and processing. The machine readable medium may include ROMs, EPROMs, EAROMs, Flash Memories and Optical disks. All of these media have the capability of storing the data acquired by the logging tool and of storing the instructions for processing the data. It would be apparent to those versed in the art that due to the amount of data being acquired and processed, it is impossible to do the processing and analysis without use of an electronic processor or computer.
Therefore, in one aspect, the present disclosure provides a method of detecting a gas influx event in a borehole fluid during drilling operations that includes: obtaining a measurement of an acoustic velocity of the borehole fluid at an acoustic sensor disposed in a borehole; obtaining a measurement of temperature of the borehole fluid at a temperature sensor disposed in the borehole; and comparing the measurement of the acoustic velocity of the borehole fluid to the measurement of the temperature of the borehole fluid to detect the gas influx event. In one embodiment, the gas influx event is detected when a change in the acoustic velocity exceeds a selected acoustic velocity threshold and a change in the temperature exceeds a selected temperature threshold. The change in the acoustic velocity exceeds the selected acoustic velocity threshold and the change in the temperature exceeds the selected temperature threshold at substantially a same time. In one embodiment, the measurement of acoustic velocity of the borehole fluid is obtained by generating an acoustic pulse in the borehole fluid at a downhole location; reflecting the generated acoustic pulse from at least two reflecting surfaces of a stepped reflector in the fluid to provide at least two reflected pulses; and determining the acoustic velocity of the borehole fluid from a difference in arrival time of the at least two reflected pulses. The method may further include providing a logarithmic plot of the acoustic velocity versus time and to a logarithmic plot of the temperature (or of the complementary temperature) versus time. The method may alternatively include comparing a first derivative of the acoustic velocity to a selected threshold value and comparing a first derivative of the temperature to a selected threshold value. The acoustic sensor and the temperature sensor are disposed in an annulus between a drill string and a borehole wall. The temperature sensor may be disposed at one of: (i) in a drill bit; (ii) proximate the drill bit; and (iii) proximate a bottomhole assembly.
In another aspect, the present disclosure provides an apparatus for detecting a gas influx event in a borehole fluid during drilling operation that includes: an acoustic sensor configured to obtain a measurement of an acoustic velocity of the borehole fluid; a temperature measuring device configured to obtain a measurement of a temperature of the borehole fluid; and a processor configured to compare the measurement of the acoustic velocity of the borehole fluid to the measurement of the temperature of the borehole fluid to determine a gas influx event. The processor may be further configured to detect the gas influx event when a change in the acoustic velocity exceeds a selected acoustic velocity threshold and a change in the temperature exceeds a selected temperature threshold. The processor may be further configured to detect the gas influx event when the change in the acoustic velocity exceeds the selected acoustic velocity threshold and a change in the temperature exceeds the selected temperature threshold at substantially a same time. In one embodiment, the acoustic sensor includes an acoustic transducer configured to generate an acoustic pulse in the borehole fluid and to detect an acoustic signal from the borehole fluid and a stepped reflector configured to provide at least two reflections of the generated acoustic pulse to the acoustic transducer. The processor may further compare a logarithmic plot of the acoustic velocity to a logarithmic plot of the temperature versus time. Alternatively, the processor may compare a first derivative of the acoustic velocity to a selected threshold value and compare a first derivative of the temperature to a selected threshold value. In one embodiment, the acoustic velocity sensor and the temperature sensor are disposed in an annulus between the drill string and borehole wall. The temperature sensor may be disposed at one of: (i) in a drill bit; (ii) proximate the drill bit; and (iii) proximate a bottomhole assembly.
In yet another aspect, the present disclosure provides a computer-readable medium having a set of instruction stored thereon that when read by a processor enable the processor to perform a method, the method including: receiving a measurement of an acoustic velocity of a borehole fluid from an acoustic sensor disposed in a borehole; receiving a measurement of temperature of the borehole fluid from a temperature sensor disposed in the borehole; and comparing the measurement of the acoustic velocity of the borehole fluid to the measurement of the temperature of the borehole fluid to detect a gas influx event.
While the foregoing disclosure is directed to the specific embodiments of the disclosure, various modifications will be apparent to those skilled in the art. It is intended that all such variations within the scope of the appended claims be embraced by the foregoing disclosure.
This application is a continuation-in-part of U.S. patent application Ser. No. 12/398,060, filed on Mar. 4, 2009, which is a continuation-in-part of U.S. patent application Ser. No. 11/841,527, filed Aug. 20, 2007, and U.S. patent application Ser. No. 11/194,365, now U.S. Pat. No. 7,523,640; and further claims priority from U.S. Provisional Patent Application Ser. No. 60/839,602 filed on Aug. 23, 2006.
Number | Name | Date | Kind |
---|---|---|---|
2244484 | Beers | Jun 1941 | A |
3776032 | Vogel | Dec 1973 | A |
4208906 | Roberts, Jr. | Jun 1980 | A |
4273212 | Dorr et al. | Jun 1981 | A |
4412130 | Winters | Oct 1983 | A |
4492865 | Murphy et al. | Jan 1985 | A |
4571693 | Birchak et al. | Feb 1986 | A |
4619267 | Lannuzel et al. | Oct 1986 | A |
4733232 | Grosso | Mar 1988 | A |
4769793 | Kniest et al. | Sep 1988 | A |
4938066 | Dorr | Jul 1990 | A |
5130950 | Orban et al. | Jul 1992 | A |
5163029 | Bryant et al. | Nov 1992 | A |
5275040 | Codazzi | Jan 1994 | A |
5635626 | Hammond et al. | Jun 1997 | A |
5741962 | Birchak et al. | Apr 1998 | A |
6029507 | Faber et al. | Feb 2000 | A |
6032516 | Takahashi et al. | Mar 2000 | A |
6050141 | Tello et al. | Apr 2000 | A |
6176323 | Weirich et al. | Jan 2001 | B1 |
6205848 | Faber et al. | Mar 2001 | B1 |
6208586 | Rorden et al. | Mar 2001 | B1 |
6250137 | Takahashi et al. | Jun 2001 | B1 |
6634214 | Thurston et al. | Oct 2003 | B1 |
6648083 | Evans et al. | Nov 2003 | B2 |
6672163 | Han et al. | Jan 2004 | B2 |
6768106 | Gzara et al. | Jul 2004 | B2 |
6817229 | Han et al. | Nov 2004 | B2 |
6829947 | Han et al. | Dec 2004 | B2 |
6957572 | Wu | Oct 2005 | B1 |
7024917 | DiFoggio | Apr 2006 | B2 |
7334651 | Wu | Feb 2008 | B2 |
20020100327 | Kersey et al. | Aug 2002 | A1 |
20020117003 | Banno et al. | Aug 2002 | A1 |
20020178787 | Matsiev et al. | Dec 2002 | A1 |
20020178805 | DiFoggio et al. | Dec 2002 | A1 |
20020184940 | Storm, Jr. et al. | Dec 2002 | A1 |
20020189367 | Gomm et al. | Dec 2002 | A1 |
20020194906 | Goodwin et al. | Dec 2002 | A1 |
20030029241 | Mandal | Feb 2003 | A1 |
20030029242 | Yaralioglu et al. | Feb 2003 | A1 |
20030051533 | James et al. | Mar 2003 | A1 |
20030101819 | Mutz et al. | Jun 2003 | A1 |
20030144746 | Hsiung et al. | Jul 2003 | A1 |
20030150262 | Han et al. | Aug 2003 | A1 |
20030172734 | Greenwood | Sep 2003 | A1 |
20030209066 | Goodwin | Nov 2003 | A1 |
20030220742 | Niedermayr et al. | Nov 2003 | A1 |
20040007058 | Rylander et al. | Jan 2004 | A1 |
20040020294 | Buckin | Feb 2004 | A1 |
20040040746 | Niedermayr et al. | Mar 2004 | A1 |
20040060345 | Eggen et al. | Apr 2004 | A1 |
20040095847 | Hassan et al. | May 2004 | A1 |
20040173017 | O'Brien | Sep 2004 | A1 |
20040194539 | Gysling | Oct 2004 | A1 |
20040216515 | Yakhno et al. | Nov 2004 | A1 |
20040236512 | DiFoggio et al. | Nov 2004 | A1 |
20050103097 | Faltum et al. | May 2005 | A1 |
20050149277 | Bailey et al. | Jul 2005 | A1 |
20050212869 | Ellson et al. | Sep 2005 | A1 |
20050223808 | Myers et al. | Oct 2005 | A1 |
20050252294 | Ariav | Nov 2005 | A1 |
20050268703 | Funck et al. | Dec 2005 | A1 |
20070022803 | DiFoggio et al. | Feb 2007 | A1 |
20080047337 | Chemali et al. | Feb 2008 | A1 |
20090173150 | DiFoggio et al. | Jul 2009 | A1 |
20090272580 | Dolman et al. | Nov 2009 | A1 |
20100315900 | DiFoggio et al. | Dec 2010 | A1 |
Number | Date | Country |
---|---|---|
WO9850680 | Nov 1998 | WO |
Entry |
---|
Bulloch, T. E.; The Investigation of Fluid Properties and Seismic Attributes for Reservoir Characterization, Thesis for degree of Master of Science in Geological Engineering, Michigan Technological University, 1999, pp. A1-A6. |
Doyle, E.F. et al.; “Plan for Surprises: Pore Pressure Challenges during the drilling of a Deepwater Exploration Well in mid-winter in Norway,” SPE/IADC 79848, SPE/IADC Drilling Conference, Amsterdam, The Netherlands, Feb. 19-21, 2003, pp. 1-8. |
Guyod, Hubert; “Temperature Well Logging,” Oil Weekly, Well Logging, Part 6, 1946, pp. 40-44. |
Havira, R. M.; “Ultrasonic Cement Bond Evaluation,” Paper N, SPWLA Twenty-Third Annual Logging Symposium, Jul. 6-9, 1982, pp. 1-11. |
Honarvar, F. et al.; Reference wavelets used for deconvolution of ultrasonic time-of-flight diffraction (ToFD) signals, 17th World Conference on Nondestructive Testing, Oct. 25-28, 2008, Shanghai, China, pp. 1-9. |
Kading, Horace W. et al.; “Temperature Surveys: The Art of Interpretation,” Am. Pet. Inst., Pub.; (United States); Journal vol. 906-14-N; Conference; API southwestern district product division spring meeting, Lubbock, Texas, USA, Mar. 12, 1969, pp. 1-20. |
Mohanty, Sitakanta; “Effect of Multiphase Fluid Saturation on the Thermal Conductivity of Geologic Media,” J. Phys. D. Appl. Phys., 30, No. 24 (Dec. 21, 1997), pp. L-80-L84. |
Reservoir Characterization Instrument, RCI Instrument Modules, pamphlet from Baker Hughes, Copyright 2000 Baker Hughes Incorporated, pp. 7-1-7-11. |
Reservoir Characterization Instrument, RCI Instrument Modules, pamphlet from Baker Hughes, Copyright 2000 Baker Hughes Incorporated, pp. 7-12-7-20. |
Reservoir Characterization Instrument, RCI Instrument Modules, pamphlet from Baker Hughes, Copyright 2000 Baker Hughes Incorporated, pp. 7-21-7-28. |
Savitzky, A. et al.; “Smoothing and Differentiation of Data by Simplified Least Squares Procedures,” Analytical Chemistry, International Gas Chromatography Symposium, vol. 36, No. 8, Jul. 1964, pp. 1627-1639 |
Weatherford, “HEL MWD System-Rapid Annular Temperature (RAT) Sensor,” http://www.weatherford.com/weatherford/groups/web/documents/weatherfordcorp/wft104872.pdf, 2 sheets. |
International Search Report and Written Opinion dated Jun. 12, 2013 for International Application No. PCT/US2013/026832. |
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20120170406 A1 | Jul 2012 | US |
Number | Date | Country | |
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60839602 | Aug 2006 | US |
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Parent | 12398060 | Mar 2009 | US |
Child | 13401503 | US | |
Parent | 11194365 | Aug 2005 | US |
Child | 12398060 | US | |
Parent | 11841527 | Aug 2007 | US |
Child | 11194365 | US |