Patent Application
20120152519
The present disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides for sensing shock during well perforating.
Attempts have been made to determine the effects of shock due to perforating on components of a perforating string. It would be desirable, for example, to prevent unsetting a production packer, to prevent failure of a perforating gun body, and to otherwise prevent or at least reduce damage to the various components of a perforating string.
Unfortunately, past attempts have not satisfactorily measured the strains, pressures, and/or accelerations, etc., produced by perforating. This makes estimations of conditions to be experienced by current and future perforating string designs unreliable.
Therefore, it will be appreciated that improvements are needed in the art. These improvements can be used, for example, in designing new perforating string components which are properly configured for the conditions they will experience in actual perforating situations.
In carrying out the principles of the present disclosure, a shock sensing tool is provided which brings improvements to the art of measuring shock during well perforating. One example is described below in which the shock sensing tool is used to prevent damage to a perforating string. Another example is described below in which sensor measurements recorded by the shock sensing tool can be used to predict the effects of shock due to perforating on components of a perforating string.
A shock sensing tool for use with well perforating is described below. In one example, the shock sensing tool can include a generally tubular structure which is fluid pressure balanced, at least one sensor which senses load in the structure, and a pressure sensor which senses pressure external to the structure.
Also described below is a well system which can include a perforating string including multiple perforating guns and at least one shock sensing tool. The shock sensing tool can be interconnected in the perforating string between one of the perforating guns and at least one of: a) another of the perforating guns, and b) a firing head.
These and other features, advantages and benefits will become apparent to one of ordinary skill in the art upon careful consideration of the detailed description of representative embodiments of the disclosure hereinbelow and the accompanying drawings, in which similar elements are indicated in the various figures using the same reference numbers.
Representatively illustrated in
In other examples, the perforating string 12 may include more or less of these components. For example, well screens and/or gravel packing equipment may be provided, any number (including one) of the perforating guns 20 and shock sensing tools 22 may be provided, etc. Thus, it should be clearly understood that the well system 10 as depicted in
One advantage of interconnecting the shock sensing tools 22 below the packer 16 and in close proximity to the perforating guns 20 is that more accurate measurements of strain and acceleration at the perforating guns can be obtained. Pressure and temperature sensors of the shock sensing tools 22 can also sense conditions in the wellbore 14 in close proximity to perforations 24 immediately after the perforations are formed, thereby facilitating more accurate analysis of characteristics of an earth formation 26 penetrated by the perforations.
A shock sensing tool 22 interconnected between the packer 16 and the upper perforating gun 20 can record the effects of perforating on the perforating string 12 above the perforating guns. This information can be useful in preventing unsetting or other damage to the packer 16, firing head 18, etc., due to detonation of the perforating guns 20 in future designs.
A shock sensing tool 22 interconnected between perforating guns 20 can record the effects of perforating on the perforating guns themselves. This information can be useful in preventing damage to components of the perforating guns 20 in future designs.
A shock sensing tool 22 can be connected below the lower perforating gun 20, if desired, to record the effects of perforating at this location. In other examples, the perforating string 12 could be stabbed into a lower completion string, connected to a bridge plug or packer at the lower end of the perforating string, etc., in which case the information recorded by the lower shock sensing tool 22 could be useful in preventing damage to these components in future designs.
Viewed as a complete system, the placement of the shock sensing tools 22 longitudinally spaced apart along the perforating string 12 allows acquisition of data at various points in the system, which can be useful in validating a model of the system. Thus, collecting data above, between and below the guns, for example, can help in an understanding of the overall perforating event and its effects on the system as a whole.
The information obtained by the shock sensing tools 22 is not only useful for future designs, but can also be useful for current designs, for example, in post-job analysis, formation testing, etc. The applications for the information obtained by the shock sensing tools 22 are not limited at all to the specific examples described herein.
Referring additionally now to
In
The detonation train 30 can transfer detonation between perforating guns 20, between a firing head (not shown) and a perforating gun, and/or between any other explosive components in the perforating string 12. In the example of
One or more pressure sensors 36 may be used to sense pressure in perforating guns, firing heads, etc., attached to the connectors 28. Such pressure sensors 36 are preferably ruggedized (e.g., to withstand ˜20000 g acceleration) and capable of high bandwidth (e.g., >20 kHz). The pressure sensors 36 are preferably capable of sensing up to ˜60 ksi (˜414 MPa) and withstanding ˜175 degrees C. Of course, pressure sensors having other specifications may be used, if desired.
Strain sensors 38 are attached to an inner surface of a generally tubular structure 40 interconnected between the connectors 28. The structure 40 is preferably pressure balanced, i.e., with substantially no pressure differential being applied across the structure.
In particular, ports 42 are provided to equalize pressure between an interior and an exterior of the structure 40. In the simplest embodiment, the ports 42 are open to allow filling of structure 40 with wellbore fluid. However, the ports 42 are preferably plugged with an elastomeric compound and the structure 40 is preferably pre-filled with a suitable substance (such as silicone oil, etc.) to isolate the sensitive strain sensors 38 from wellbore contaminants. By equalizing pressure across the structure 40, the strain sensor 38 measurements are not influenced by any differential pressure across the structure before, during or after detonation of the perforating guns 20.
The strain sensors 38 are preferably resistance wire-type strain gauges, although other types of strain sensors (e.g., piezoelectric, piezoresistive, fiber optic, etc.) may be used, if desired. In this example, the strain sensors 38 are mounted to a strip (such as a KAPTON™ strip) for precise alignment, and then are adhered to the interior of the structure 40.
Preferably, four full Wheatstone bridges are used, with opposing 0 and 90 degree oriented strain sensors being used for sensing axial and bending strain, and +/−45 degree gauges being used for sensing torsional strain.
The strain sensors 38 can be made of a material (such as a KARMA™ alloy) which provides thermal compensation, and allows for operation up to ˜150 degrees C. Of course, any type or number of strain sensors may be used in keeping with the principles of this disclosure.
The strain sensors 38 are preferably used in a manner similar to that of a load cell or load sensor. A goal is to have all of the loads in the perforating string 12 passing through the structure 40 which is instrumented with the sensors 38.
Having the structure 40 fluid pressure balanced enables the loads (e.g., axial, bending and torsional) to be measured by the sensors 38, without influence of a pressure differential across the structure. In addition, the detonating cord 32 is housed in a tube 33 which is not rigidly secured at one or both of its ends, so that it does not share loads with, or impart any loading to, the structure 40.
In other examples, the structure 40 may not be pressure balanced. A clean oil containment sleeve could be used with a pressure balancing piston. Alternatively, post-processing of data from an uncompensated strain measurement could be used in order to approximate the strain due to structural loads. This estimation would utilize internal and external pressure measurements to subtract the effect of the pressure loads on the strain gauges, as described for another configuration of the tool 22 below.
A temperature sensor 44 (such as a thermistor, thermocouple, etc.) can be used to monitor temperature external to the tool. Temperature measurements can be useful in evaluating characteristics of the formation 26, and any fluid produced from the formation, immediately following detonation of the perforating guns 20. Preferably, the temperature sensor 44 is capable of accurate high resolution measurements of temperatures up to ˜170 degrees C.
Another temperature sensor (not shown) may be included with an electronics package 46 positioned in an isolated chamber 48 of the tool 22. In this manner, temperature within the tool 22 can be monitored, e.g., for diagnostic purposes or for thermal compensation of other sensors (for example, to correct for errors in sensor performance related to temperature change). Such a temperature sensor in the chamber 48 would not necessarily need the high resolution, responsiveness or ability to track changes in temperature quickly in wellbore fluid of the other temperature sensor 44.
The electronics package 46 is connected to at least the strain sensors 38 via pressure isolating feed-throughs or bulkhead connectors 50. Similar connectors may also be used for connecting other sensors to the electronics package 46. Batteries 52 and/or another power source may be used to provide electrical power to the electronics package 46.
The electronics package 46 and batteries 52 are preferably ruggedized and shock mounted in a manner enabling them to withstand shock loads with up to ˜10000 g acceleration. For example, the electronics package 46 and batteries 52 could be potted after assembly, etc.
In
The pressure sensor 56 is used to monitor pressure external to the tool 22, for example, in an annulus 62 formed radially between the perforating string 12 and the wellbore 14 (see
The temperature sensor 58 may be used for monitoring temperature within the tool 22. This temperature sensor 58 may be used in place of, or in addition to, the temperature sensor described above as being included with the electronics package 46.
The accelerometer 60 is preferably a piezoresistive type accelerometer, although other types of accelerometers may be used, if desired. Suitable accelerometers are available from Endevco and PCB (such as the PCB 3501A series, which is available in single axis or triaxial packages, capable of sensing up to ˜60000 g acceleration).
In
Also visible in
Note that it can be many hours or even days between assembly of the tool 22 and detonation of the perforating guns 20. In order to preserve battery power, the electronics package 46 is preferably programmed to “sleep” (i.e., maintain a low power usage state), until a particular signal is received, or until a particular time period has elapsed.
The signal which “wakes” the electronics package 46 could be any type of pressure, temperature, acoustic, electromagnetic or other signal which can be detected by one or more of the sensors 36, 38, 44, 56, 58, 60. For example, the pressure sensor 56 could detect when a certain pressure level has been achieved or applied external to the tool 22, or when a particular series of pressure levels has been applied, etc. In response to the signal, the electronics package 46 can be activated to a higher measurement recording frequency, measurements from additional sensors can be recorded, etc.
As another example, the temperature sensor 58 could sense an elevated temperature resulting from installation of the tool 22 in the wellbore 14. In response to this detection of elevated temperature, the electronics package 46 could “wake” to record measurements from more sensors and/or higher frequency sensor measurements.
As yet another example, the strain sensors 38 could detect a predetermined pattern of manipulations of the perforating string 12 (such as particular manipulations used to set the packer 16). In response to this detection of pipe manipulations, the electronics package 46 could “wake” to record measurements from more sensors and/or higher frequency sensor measurements.
The electronics package 46 depicted in
Referring additionally now to
In
A relatively thin protective sleeve 72 is used to prevent damage to the strain sensors 38, which are attached to an exterior of the structure 40 (see
Note that there is preferably no pressure differential across the sleeve 72, and a suitable substance (such as silicone oil, etc.) is preferably used to fill the annular space between the sleeve and the structure 40. The sleeve 72 is not rigidly secured at one or both of its ends, so that it does not share loads with, or impart loads to, the structure 40.
Any of the sensors described above for use with the tool 22 configuration of
In general, it is preferable for the structure 40 (in which loading is measured by the strain sensors 38) to experience dynamic loading due only to structural shock by way of being pressure balanced, as in the configuration of
Although the perforating string 12 described above is of the type used in tubing-conveyed perforating, it should be clearly understood that the principles of this disclosure are not limited to tubing-conveyed perforating. Other types of perforating (such as, perforating via coiled tubing, wireline or slickline, etc.) may incorporate the principles described herein. Note that the packer 16 is not necessarily a part of the perforating string 12.
It may now be fully appreciated that the above disclosure provides several advancements to the art. In the example of the shock sensing tool 22 described above, the effects of perforating can be conveniently measured in close proximity to the perforating guns 20.
In particular, the above disclosure provides to the art a well system 10 which can comprise a perforating string 12 including multiple perforating guns 20 and at least one shock sensing tool 22. The shock sensing tool 22 can be interconnected in the perforating string 12 between one of the perforating guns 20 and at least one of: a) another of the perforating guns 20, and b) a firing head 18.
The shock sensing tool 22 may be interconnected in the perforating string 12 between the firing head 18 and the perforating guns 20.
The shock sensing tool 22 may be interconnected in the perforating string 12 between two of the perforating guns 20.
Multiple shock sensing tools 22 can be longitudinally distributed along the perforating string 12.
At least one of the perforating guns 20 may be interconnected in the perforating string 12 between two of the shock sensing tools 22.
A detonation train 30 may extend through the shock sensing tool 22.
The shock sensing tool 22 can include a strain sensor 38 which senses strain in a structure 40. The structure 40 may be fluid pressure balanced.
The shock sensing tool 22 can include a sensor 38 which senses load in a structure 40. The structure 40 may transmit all structural loading between the one of the perforating guns 20 and at least one of: a) the other of the perforating guns 20, and b) the firing head 18.
Both an interior and an exterior of the structure 40 may be exposed to pressure in an annulus 62 between the perforating string 12 and a wellbore 14. The structure 40 may be isolated from pressure in the wellbore 14.
The shock sensing tool 22 can include a pressure sensor 56 which senses pressure in an annulus 62 formed between the shock sensing tool 22 and a wellbore 14.
The shock sensing tool 22 can include a pressure sensor 36 which senses pressure in one of the perforating guns 20.
The shock sensing tool 22 may begin increased recording of sensor measurements in response to sensing a predetermined event.
Also described by the above disclosure is a shock sensing tool 22 for use with well perforating. The shock sensing tool 22 can include a generally tubular structure 40 which is fluid pressure balanced, at least one sensor 38 which senses load in the structure 40 and a pressure sensor 56 which senses pressure external to the structure 40.
The at least one sensor 38 may comprise a combination of strain sensors which sense axial, bending and torsional strain in the structure 40.
The shock sensing tool 22 can also include another pressure sensor 36 which senses pressure in a perforating gun 20 attached to the shock sensing tool 22.
The shock sensing tool 22 can include an accelerometer 60 and/or a temperature sensor 44, 58.
A detonation train 30 may extend through the structure 40.
A flow passage 68 may extend through the structure 40.
The shock sensing tool 22 may include a perforating gun connector 28 at an end of the shock sensing tool 22.
The shock sensing tool 22 may include a non-volatile memory 66 which stores sensor measurements.
It is to be understood that the various embodiments described herein may be utilized in various orientations, such as inclined, inverted, horizontal, vertical, etc., and in various configurations, without departing from the principles of the present disclosure. The embodiments are described merely as examples of useful applications of the principles of the disclosure, which is not limited to any specific details of these embodiments.
In the above description of the representative embodiments, directional terms, such as “above,” “below,” “upper,” “lower,” etc., are used for convenience in referring to the accompanying drawings. In general, “above,” “upper,” “upward” and similar terms refer to a direction toward the earth's surface along a wellbore, and “below,” “lower,” “downward” and similar terms refer to a direction away from the earth's surface along the wellbore.
Of course, a person skilled in the art would, upon a careful consideration of the above description of representative embodiments of the disclosure, readily appreciate that many modifications, additions, substitutions, deletions, and other changes may be made to the specific embodiments, and such changes are contemplated by the principles of the present disclosure. Accordingly, the foregoing detailed description is to be clearly understood as being given by way of illustration and example only, the spirit and scope of the present invention being limited solely by the appended claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| PCT/US10/61102 | Dec 2010 | US | national |
This application claims the benefit under 35 USC §119 of the filing date of International Application Serial No. PCT/US10/61102, filed 17 Dec. 2010. The entire disclosure of this prior application is incorporated herein by this reference.
