OPTIMAL PHASING OF CHARGES IN A PERFORATING SYSTEM AND METHOD
An optimal phasing perforating phased gun system and method for accurate perforation in a deviated/horizontal wellbore is disclosed. The system/method includes a gun string assembly (GSA) deployed in a wellbore with shaped charges in clusters. Within a cluster, the charges are separated into individual banks with a phase angle between the charges in each bank and an offset angle between banks. The number of charges per cluster, the phase angle and the offset angle are optimized such that there is a maximum probability of perforating into a low compression region in an upward and downward direction.
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The present invention relates generally to perforation guns that are used in the oil and gas industry to explosively perforate well casing and underground hydrocarbon bearing formations, and more particularly to an optimally phased perforating apparatus for explosively perforating a well casing and its surrounding underground hydrocarbon bearing formation.
PRIOR ART AND BACKGROUND OF THE INVENTION Prior Art BackgroundDuring a well completion process, a gun string assembly is positioned in an isolated zone in the wellbore casing. The gun string assembly comprises a plurality of perforating guns coupled to each other either through tandems or subs. The perforating gun is then fired, creating holes through the casing and the cement and into the targeted rock. These perforating holes connect the rock holding the oil and gas and the well bore. “During the completion of an oil and/or gas well, it is common to perforate the hydrocarbon containing formation with explosive charges to allow inflow of hydrocarbons to the well bore. These charges are loaded in a perforation gun and are typically shaped charges that produce an explosive formed penetrating jet in a chosen direction” U.S. Pat. No. 7,441,601.
Hydrocarbon fracturing tunnels have certain preferred orientations where the effectiveness of extracting oil/gas is greatest i.e., when a perforation is aligned along the tunnels, oil/gas flows though the perforation tunnels without taking an alternate path that may become a restrictive path creating high tortuosity conditions.
It has been shown in studies that the fractures initiate close to the wellbore casing in an upward and downward direction.
By design, each perforation is expected to be involved in the fracture treatment. If all perforations are involved, and the perforations are shot with 0°, 60°, 90°, 120°, or 180° phasing, multiple fracture planes may be created, leading to substantial near wellbore friction and difficulty in placing the planned fracturing treatment. Field results indicate that there is a single dominant perforation tunnel per stage. Therefore, there is a need for minimal multiple fracture initiations that do not create ineffective fracture planes. Various prior art phasing in a perforating gun (0302) in a well casing (0301) is illustrated in
Currently, 1 to 12 perforation holes per stage are shot which will reconnect to the predominant fracturing plane during fracturing treatment. Most stages are completed with 6 shots per cluster and 6 shots per foot (“spf”) and at 60 degrees for obvious statistical reasons. Some of the perforation tunnels cause energy and pressure loss during fracturing treatment which reduces the intended pressure in the fracture tunnels. For example, if a 100 bpm (barrels per minute) fracture fluid is pumped into each fracture zone at 10000 PSI with an intention to fracture each perforation tunnel at 2-3 bpm, most of the energy is lost in ineffective fractures that have higher tortuosity reducing the injection rate per fracture to substantially less than 2-3 bpm. Consequently, the extent of fracture length is significantly reduced resulting in less oil and gas flow during production. Therefore, there is a need for a system to achieve the highest and optimal injection rate per perforation tunnel so that a maximum fracture length is realized. The more energy put through each perforation tunnel, the more fluid travels through the preferred fracturing plane, the further the fracture extends. Ideally, 1000 feet of fracture length from the wellbore is desired. Therefore, there is a need to get longer extension of fractures which have minimal tortuosity. For example, in order to achieve 2 bpm in each perforation tunnel, a total injection rate of 100 bpm at 1000 psi for 48 perforation tunnels requires 12 clusters each with 4 charges. Therefore, there is a need to shoot more zones with 4 perforating holes in each cluster that are oriented 2 up and 2 down. Active orientation systems commonly used such as 0 degrees or 180 degree orientations, have an accuracy of orientation that is estimated to be +−20 degrees with an external orientation and ±− with an internal orientation. There is a need to improve the chances of proper placement without an active orientation system.
Perforation and fracturing are based on the premise that every perforation will be in communication with a hydraulic fracture and will be contributing fluid during the treatment at the pre-determined rate. Therefore, if any perforation does not participate, then the incremental rate per perforation of every other perforation is increased, resulting in higher perforation friction. Therefore, there is a need to angle and space charges to facilitate the fracturing process to achieve maximum production efficiency.
Prior art U.S. Pat. No. 7,303,017A discloses “a method includes arranging shaped charges in a perforating gun to produce perforation holes in a helical pattern that is defined in part by a phase angle; and choosing four adjacent perforation holes to be created that are adjacent nearest neighbors. The distances are determined between three of the four adjacent perforation holes to be created. A standard deviation is minimized between the three adjacent perforation holes. The phase angle is set based on the minimization.” However, U.S. Pat. No. 7,303,017A does not teach an optimal phasing of the charges in the bank so that charges perforate within desired perforation angles in a low compression region especially for a deviated well.
Deficiencies in the Prior ArtThe prior art as detailed above suffers from the following deficiencies:
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- Prior art perforation phasing systems do not provide for efficiently reducing tortuosity and energy loss in a perforation tunnel with minimum number of shots per foot.
- Prior art perforation phasing systems do not provide for longer extension of fractures which have minimal tortuosity with minimum number of shots per foot.
- Prior art perforation phasing systems do not provide for the highest and optimal injection rate per perforation tunnel so that a maximum fracture length is realized with minimum number of shots per foot in a cluster.
- Prior art perforation phasing systems do not provide for achieving a probability greater than 50% for perforating within +−15° of the upward and downward low compression region.
- Prior art perforation phasing systems do not provide for an optimal phasing of the charges in the perforating gun per cluster in order to achieve maximum perforation and fracturing efficiency.
- Prior art perforation phasing systems do not have an optimal statistical chance of perforation placement when less than or more than 6 shots are placed in a cluster.
While some of the prior art may teach some solutions to several of these problems, the core issue of reacting to unsafe gun pressure has not been addressed by prior art.
OBJECTIVES OF THE INVENTIONAccordingly, the objectives of the present invention are (among others) to circumvent the deficiencies in the prior art and affect the following objectives:
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- Provide for efficiently reducing tortuosity and energy loss in a perforation tunnel with minimum number of shots per foot.
- Provide for longer extension of fractures which have minimal tortuosity with minimum number of shots per foot.
- Provide for the highest and optimal injection rate per perforation tunnel so that a maximum fracture length is realized with minimum number of shots per foot in a cluster.
- Provide for improving the probability to at least 50% for perforating within +−15° of the upward and downward low compression region.
- Provide for an optimal phasing of the charges in the perforating gun per cluster in order to achieve maximum perforation and fracturing efficiency.
- Provide for perforation phasing systems that have an optimal statistical chance of perforation placement when less than or more than 6 shots are placed in a cluster.
While these objectives should not be understood to limit the teachings of the present invention, in general these objectives are achieved in part or in whole by the disclosed invention that is discussed in the following sections. One skilled in the art will no doubt be able to select aspects of the present invention as disclosed to affect any combination of the objectives described above.
BRIEF SUMMARY OF THE INVENTION System OverviewThe present invention in various embodiments addresses one or more of the above objectives in the following manner. The present invention provides a system that includes an optimal phasing perforating phased gun system and method for accurate perforation in a deviated/horizontal. The system/method includes a gun string assembly (GSA) deployed in a wellbore with shaped charges in clusters. Within a cluster, the charges are separated into individual banks with a phase angle between the charges in each bank and an offset angle between banks. The number of charges per cluster, the phase angle and the offset angle are optimized such that there is a maximum probability of perforating into a low compression region in an upward and downward direction. The fracture treatment through the perforations in the low compression regions create minimal tortuosity paths for longer extension of fractures that enables efficient oil and gas flow rates during production.
Method OverviewThe present invention system may be utilized in the context of an overall optimal phasing perforating method, wherein the phased perforating gun as described previously is controlled by a method having the following steps:
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- (1) selecting a gun system for each cluster in a stage with the best statistical probability for the desired number of perforations in that cluster;
- (2) positioning a phased perforating gun system in a wellbore casing; and
- (3) perforating through the phased perforating gun system into a hydrocarbon formation such that at least one of the first plurality of charges and at least one of the second plurality of charges perforate within a upward perforation angle and a downward perforation angle; the upward perforation angle subtends in an upward direction about a center of the perforating gun and the downward perforation angle subtends in a downward direction about the center of the perforating gun.
Integration of this and other preferred exemplary embodiment methods in conjunction with a variety of preferred exemplary embodiment systems described herein in anticipation by the overall scope of the present invention.
For a fuller understanding of the advantages provided by the invention, reference should be made to the following detailed description together with the accompanying drawings wherein:
While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detailed preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiment illustrated.
The numerous innovative teachings of the present application will be described with particular reference to the presently preferred embodiment, wherein these innovative teachings are advantageously applied to the particular problems of optimal phasing perforating gun system and method. However, it should be understood that this embodiment is only one example of the many advantageous uses of the innovative teachings herein. In general, statements made in the specification of the present application do not necessarily limit any of the various claimed inventions. Moreover, some statements may apply to some inventive features but not to others.
An exemplary embodiment of the present invention may be generally illustrated in
The bank (0700) may comprise charges (0701, 0702, 0703, 0704) and the bank (0710) may comprise charges (0711, 0712, 0713, 0714). The plural shaped charges in the perforating gun together in bank (0700) and bank (0710) may herein be referred to as “cluster”. Even though four charges have been shown in each of the banks in
Referring to
According to a preferred exemplary embodiment, the number of charges in each of the banks may range from 2 to 24. According to a more preferred exemplary embodiment, the number of charges in each of the banks may range from 2 to 8. According to a most preferred exemplary embodiment, the number of charges in each of the banks may range from 2 to 6. For example, the bank (0700) may comprise 2 to 24 charges and bank (0710) may comprise 2 to 24 charges. According to a preferred exemplary embodiment, the offset angle ranges from 1 to 90°. According to a more preferred exemplary embodiment, the offset angle of the shaped charges between the banks may range from 10° to 45°. According to a most preferred exemplary embodiment, the offset angle of the shaped charges between the banks may range from 15° to 30°. The offset angle may be the phase angle between charge 0701 and charge 0711. The offset angle between 0702 and 0712 would be same if the phase angles of charges in both the banks are the same. In the illustration shown in
In the illustration presented in
The offset angle, also referred to as offset phase angle, between two banks may also be achieved by physically rotating one bank with respect to the other bank. As illustrated in
One of the banks within the cluster may be at the best orientation and therefore be the dominant bank within the cluster. The clusters will also be balanced as each cluster in a stage will have a statistical probability of having a bank with charges phased to perforate within an arc in the low compression zone. For example, referring to
As illustrated in Table 1.0, the number of banks, and charges per bank may be selected to achieve a desired probability for a perforation angle within 30° or any other angle. The combination of charges per bank, number of banks, phase angle and offset angle may be chosen per cluster based on the diameter of the perforating gun, the length of the gun and the size of the gun. For example, a 2 foot gun may accommodate 12 charges or shots with 1 foot loaded and 1 foot for end connections, a 3-ft gun may accommodate 12 shots and a 4-ft gun may accommodate 18 shots. A conventional prior art perforating gun is generally loaded with 6 shots per foot (SPF) at a 60 degree phasing. With the 60° phasing, the probability of perforating within 60° arc which includes 60° of the upward and downward low compression region is 100%. The probability of perforating within 30° of the upward and downward low compression region is 50%. Even with a doubleshot at the same phasing, the probability remains the same but requires 12 shots spanning 2 feet. However, the probability substantially doubles with an exemplary configuration that may include a 2 bank, 6 charges per bank, 60° phasing, and 30° offset angle. The probability of perforating within 15° of the upward and downward low compression region is almost 100%. Therefore, the exemplary configurations illustrated in Table 1.0 provides for a more efficient perforations so that fractures initiate in the low compression region adjacent to the perforating gun for achieving maximum fracture efficiency. Prior art guns may be loaded at the normal shots per foot with charges loaded at 6 SPF at 60° phasing, 4 SPF at 90° phasing, 5 SPF at 72° phasing and 3 SPF 120° phasing. However, according to an exemplary embodiment, a 10 shot gun may be loaded at nearly 6 SPF density or a variable density. According to a preferred exemplary embodiment, the perforation angle may range from 0° to 30° and/or within +−15°. The upward perforation angle may be substantially the same as the downward perforation angle if the phase angle is the same for all the charges within a bank.
The size of the perforation holes are different due to the fact that the perforating gun is closer to the side wall of the casing in the downward direction. The perforating hole in the downward direction is sometimes twice as large as the perforating hole in the upward direction. According to a preferred exemplary embodiment, the configurations of Table 1.0, along with orienting the charges, compensate for the disproportionate perforating hole sizes to achieve a 50/50% production flow from both upward and downward low compression zones.
According to a preferred exemplary embodiment, the charges in the first bank and the charges in the second bank may be further angled to place preferred initiation points on a transverse plane to the wellbore casing. The transverse plane may be perpendicular to the longitudinal axis of the wellbore casing. The initiation points may or may not intersect with each other, but charges may be oriented such that the initiation points intersect the preferred fracturing plane so that the fractures created from the initiation points create minimal tortuosity and longer extension of fractures. The initiation points in the preferred plane are particularly significant for wellbore completions to achieve maximum efficiency during oil and gas production. It has been known through several field studies and field data that the preferred plane is transverse about the horizontal direction of the wellbore casing. Initiation points are inherently present in perforation tunnels when shaped charges perforate. Not every point in the perforation tunnel is preferred. The preferred initiation points may lie at the end of the clear tunnel (tip) of the perforation tunnels and furthermore the preferred initiation points lie in a preferred fracturing plane. A fracturing fluid is then pumped at high pressures so that the fracture fluid extends the fractures to the maximum extent in the preferred perforating orientation. The extent of the fracture length extending radially outward from the wellbore casing may be 1000 feet according to a preferred exemplary embodiment. According to another preferred exemplary embodiment, the charges in at least two of the perforating banks are configured to place preferred initiation points on a single transverse plane to said wellbore casing. According to another preferred exemplary embodiment the charges in at least two of the perforating banks are configured to place preferred initiation points on a plurality of planes. Plurality of planes may be transverse to the wellbore casing. For example, the charges (0701, 0702, 0703, 0704) in bank (0700) may be oriented such that they intersect a first preferred fracturing plane while charges (0711, 0712, 0713, 0714) in bank (0710) may be oriented such that they intersect a second preferred fracturing plane that may be substantially parallel to the first preferred fracturing plane. Both the first preferred fracturing plane and the second preferred fracturing plane are transverse to the longitudinal axis of the wellbore casing.
Preferred Exemplary 8-Shot 2-Bank Phased Perforating Gun SystemSimilar to
An exemplary embodiment of the present invention may be generally illustrated in
The bank (0800) may comprise charges (0801, 0802, 0803), the bank (0810) may comprise charges (0811, 0812, 0813) and the bank (0820) may comprise charges (0821, 0822, 0823). The plural shaped charges in the perforating gun together in the bank (0800), the bank (0810) and the bank (0820) may herein be referred to as “cluster”. Even though three charges have been shown in each of the banks in
Referring to
According to a preferred exemplary embodiment, the offset angle ranges from 1 to 90 degrees. According to a more preferred exemplary embodiment, the offset angle of the shaped charges between the banks may range from 10° to 60°. According to a most preferred exemplary embodiment, the offset angle of the shaped charges between the banks may range from 15° to 30°. The offset angle may be the phase angle between charge 0801 and charge 0811. The offset angle between 0802 and 0812 would be same if the phase angles of charges in both the banks are the same. In the illustration shown in
In the illustration shown in
As illustrated in
Similar to
Similar to
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Similar to
Similar to
Similar to
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Similar to
As generally seen in the flow chart of
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- (1) selecting a gun system for each cluster in a stage with the best statistical probability for a desired number of perforations in that cluster (1701);
- (2) positioning a phased perforating gun in a wellbore casing (1702); and
- (3) perforating through the phased perforating gun into a hydrocarbon formation such that at least one of a first plurality of charges and at least one of a second plurality of charges perforate within an upward perforation angle and a downward perforation angle; the upward perforation angle subtends in an upward direction about a center of the perforating gun and the downward perforation angle subtends in a downward direction about the center of the perforating gun (1703).
The present invention system anticipates a wide variety of variations in the basic theme of a phased perforating gun system for use in a wellbore casing comprising a plurality of perforating banks; the plurality of perforating banks arranged in a cluster, wherein:
the plurality of perforating banks comprise a first perforating bank and a second perforating bank;
the first perforating bank comprises a first plurality of charges; the first plurality of charges phased at a first phase angle to each other;
the second perforating bank comprises a second plurality of charges; the second plurality of charges phased at a second phase angle to each other;
the first phase angle and the second phase angle angularly offset by a first offset phase angle; and
at least one of the first plurality of charges and at least one of the second plurality of charges are configured to perforate into a low compressive region in a hydrocarbon formation; the low compressive region proximal to the wellbore casing.
This general system summary may be augmented by the various elements described herein to produce a wide variety of invention embodiments consistent with this overall design description.
Method SummaryThe present invention method anticipates a wide variety of variations in the basic theme of implementation, but can be generalized as a phased perforating method for use in a wellbore casing operating in conjunction a phased perforating gun system comprising a plurality of perforating banks; the plurality of perforating banks arranged in a cluster, wherein:
the plurality of perforating banks comprise a first perforating bank and a second perforating bank;
the first perforating bank comprises a first plurality of charges; the first plurality of charges phased at a first phase angle to each other;
the second perforating bank comprises a second plurality of charges; the second plurality of charges phased at a second phase angle to each other;
the first phase angle and the second phase angle angularly offset by a first offset phase angle; and
at least one of the first plurality of charges and at least one of the second plurality of charges are configured to perforate into a low compressive region in a hydrocarbon formation; the low compressive region proximal to the wellbore casing;
wherein the method comprises the steps of:
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- (1) selecting a gun system for each cluster in a stage with the best statistical probability for the desired number of perforations in that cluster;
- (2) positioning the phased perforating gun system in the wellbore casing; and
- (3) perforating through the phased perforating gun into a hydrocarbon formation such that at least one of the first plurality of charges and at least one of the second plurality of charges perforate within an upward perforation angle and a downward perforation angle; the upward perforation angle subtends in an upward direction about a center of the perforating gun and the downward perforation angle subtends in a downward direction about the center of the perforating gun.
This general method summary may be augmented by the various elements described herein to produce a wide variety of invention embodiments consistent with this overall design description.
System/Method VariationsThe present invention anticipates a wide variety of variations in the basic theme of oil and gas extraction. The examples presented previously do not represent the entire scope of possible usages. They are meant to cite a few of the almost limitless possibilities.
This basic system and method may be augmented with a variety of ancillary embodiments, including but not limited to:
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- An embodiment wherein when perforating, at least one of the first plurality of charges and at least one of the second plurality of charges are configured to perforate within an upward perforation angle and a downward perforation angle; the upward perforation angle subtends in an upward direction about a center of the wellbore casing and the downward perforation angle subtends in a downward direction about the center of the wellbore casing.
- An embodiment wherein the orientation of the wellbore casing is substantially horizontal.
- An embodiment wherein the orientation of the wellbore casing is deviated.
- An embodiment wherein the first plurality of charges are equally spaced and the second plurality of charges are equally spaced.
- An embodiment wherein a number of the first plurality of charges range from 2 to 24.
- An embodiment wherein a number of the first plurality of charges range from 2 to 24.
- An embodiment wherein the first phase angle ranges from 1 to 359 degrees.
- An embodiment wherein the second phase angle ranges from 1 to 359 degrees.
- An embodiment wherein the first offset phase angle ranges from 1 to 90 degrees.
- An embodiment wherein the upward perforation angle ranges from 0 to 45 degrees.
- An embodiment wherein the downward perforation angle ranges from 0 to 45 degrees.
- An embodiment wherein the plurality of perforating banks further comprises a third perforating bank;
- the third perforating bank comprises a third plurality of charges; the third plurality of charges are phased at a third phase angle to each other;
- the first phase angle and the second phase angle are angularly offset by offset phase angle; the second phase angle and the third phase angle are angularly offset by the second offset phase angle;
- when perforating, at least one of the first plurality of charges, at least one of the second plurality of charges, and at least one of the third plurality of charges are configured to perforate within an upward perforation angle and a downward perforation angle; the upward perforation angle subtends in an upward direction about a center of the perforating gun and the downward perforation angle subtends in a downward direction about the center of the perforating gun.
- An embodiment wherein a number of the third plurality of charges range from 2 to 24.
- An embodiment wherein the third phase angle ranges from 1 to 359 degrees.
- An embodiment wherein the second offset phase angle ranges from 1 to 90 degrees.
- An embodiment wherein the upward perforation angle ranges from 1 to 30 degrees.
- An embodiment wherein the downward perforation angle ranges from 1 to 30 degrees.
- An embodiment wherein the first plurality of charges and the second are further angled to place preferred initiation points on a transverse plane to the wellbore casing.
- An embodiment wherein charges in at least two of the plurality of perforating banks are configured to place preferred initiation points on a single transverse plane to the wellbore casing.
- An embodiment wherein charges in at least two of the plurality of perforating banks are configured to place preferred initiation points on a plurality of planes; the plurality of planes transverse to the wellbore casing.
- An embodiment wherein the second perforating bank is rotated about an orienting reference point by the first offset phase angle.
One skilled in the art will recognize that other embodiments are possible based on combinations of elements taught within the above invention description.
CONCLUSIONAn optimal phasing perforating phased gun system and method for accurate perforation in a deviated/horizontal wellbore has been disclosed. The system/method includes a gun string assembly (GSA) deployed in a wellbore with shaped charges in clusters. Within a cluster, the charges are separated into individual banks with a phase angle between the charges in each bank and an offset angle between banks. The number of charges per cluster, the phase angle and the offset angle are optimized such that there is a maximum probability of perforating into a low compression region in an upward and downward direction.
Claims
1. A phased perforating gun system for use in a wellbore casing comprising a plurality of perforating banks; said plurality of perforating banks arranged in a cluster, wherein:
- said plurality of perforating banks comprise a first perforating bank and a second perforating bank.;
- said first perforating bank comprises a first plurality of charges; said first plurality of charges phased at a first phase angle to each other;
- the first perforating bank having no charges in the same transverse plane;
- said second perforating bank comprises a second plurality of charges; said second plurality of charges phased at a second phase angle to each other;
- the second perforating bank having no charges in the same transverse plane:
- said first phase angle and said second phase angle angularly offset by a first offset phase angle;
- said first phase angle equal to 360 degrees divided by a number of said first plurality of charges;
- said second phase angle equal to 360 degrees divided by a number of said second plurality of charges;
- at least one of said first plurality of charges or at least one of said second plurality of charges are configured to perforate within an upward perforation angle with a probability greater than 50%; said upward perforation angle ranges from 0 degrees to 30 degrees;
- at least one of said first plurality of charges or at least one of said second plurality of charges are configured to perforate within an downward perforation angle with a probability greater than 50%; said downward perforation angle ranges from 0 degrees to 30 degrees; and
- said upward perforation angle subtends in an upward direction about a center of said wellbore casing and said downward perforation angle subtends in a downward direction about said center of said wellbore casing.
2. (canceled)
3. The phased perforating gun system of claim 1 wherein said wellbore casing is substantially horizontal.
4. The phased perforating gun system of claim 1 wherein said wellbore casing is deviated.
5. The phased perforating gun system of claim 1 wherein said first plurality of charges are equally spaced and said second plurality of charges are equally spaced.
6. The phased perforating gun system of claim 1 wherein said first plurality of charges are unequally spaced and said second plurality of charges are unequally spaced.
7. The phased perforating gun system of claim 1 wherein a number of said first plurality of charges range from 2 to 24.
8. The phased perforating gun system of claim 1 wherein a number of said second plurality of charges range from 2 to 24.
9. The phased perforating gun system of claim 1 wherein said first phase angle ranges from 15 to 180 degrees.
10. The phased perforating gun system of claim 1 wherein said second phase angle ranges from 15 to 180 degrees.
11. The phased perforating gun system of claim 1 wherein said first offset phase angle ranges from 1 to 90 degrees.
12. (canceled)
13. (canceled)
14. The phased perforating gun system of claim 1 wherein said plurality of perforating banks further comprises a third perforating bank;
- said third perforating bank comprises a third plurality of charges; said third plurality of charges are phased at a third phase angle to each other;
- said third phase angle equal to 360 degrees divided by a number of said third plurality of charges;
- the third perforating bank having no charges in the same transverse plane;
- said first phase angle and said second phase angle are angularly offset by said first offset phase angle; said second phase angle and said third phase angle are angularly offset by a second offset phase angle;
- when perforating, at least one of said first plurality of charges, at least one of said second plurality of charges, and at least one of said third plurality of charges are configured to perforate within said upward perforation angle and said downward perforation angle; said upward perforation angle subtends in said upward direction about said center of said perforating gun and said downward perforation angle subtends in said downward direction about said center of said perforating gun.
15. The phased perforating gun system of claim 14 wherein a number of said third plurality of charges range from 2 to 24.
16. The phased perforating gun system of claim 14 wherein said third phase angle ranges from 15 to 180 degrees.
17. The phased perforating gun system of claim 14 wherein said second offset phase angle ranges from 1 to 90 degrees.
18. The phased perforating gun system of claim 14 wherein said upward perforation angle ranges from 1 to 30 degrees.
19. The phased perforating gun system of claim 14 wherein said downward perforation angle ranges from 1 to 30 degrees.
20. The phased perforating gun system of claim 1 wherein said first plurality of charges and said second plurality of charges are further angled to place preferred initiation points on a transverse plane to said wellbore casing.
21. The phased perforating gun system of claim 14 wherein charges in at least two of said plurality of perforating banks are configured to place preferred initiation points on a single transverse plane to said wellbore casing.
22. The phased perforating gun system of claim 14 wherein charges in at least two of said plurality of perforating banks are configured to place preferred initiation points on a plurality of planes; said plurality of planes transverse to said wellbore casing.
23. The phased perforating gun system of claim 1 wherein said second perforating bank is rotated about an orienting reference point by said first offset phase angle.
24. A phased perforating method for use in a wellbore casing operating in conjunction with a phased perforating gun system comprising a plurality of perforating banks; said plurality of perforating banks arranged in a cluster, wherein:
- said plurality of perforating banks comprise a first perforating bank and a second perforating bank;
- said first perforating bank comprises a first plurality of charges; said first plurality of charges phased at a first phase angle to each other;
- the first perforating bank having no charges in the same transverse plane;
- said second perforating bank comprises a second plurality of charges; said second plurality of charges phased at a second phase angle to each other;
- the first perforating hank having no charges in the same transverse plane;
- said first phase angle and said second phase angle angularly offset by a first offset phase angle;
- said first phase angle equal to 360 degrees divided by the number of said first plurality of charges; and
- said second phase angle equal to 360 degrees divided by number of said second plurality of charges;
- wherein said method comprises the steps of: (1) selecting a gun system for each cluster in a stage with the best statistical probability for a desired number of perforations in said cluster; (2) positioning said phased perforating gun system in said wellbore casing; and (3) perforating through said phased perforating gun system into a hydrocarbon formation such that at least one of said first plurality of charges and at least one of said second plurality of charges perforate within an upward perforation angle and at least one of said first plurality of charges and at least one of said second plurality of charges perforate within a downward perforation angle; said upward perforation angle subtends in an upward direction about a center of said perforating gun and said downward perforation angle subtends in a downward direction about said center of said perforating gun; said upward perforation angle ranges from 0 degrees to 30 degrees and said downward perforation angle ranges from 0 degrees to 30 degrees.
25. A phased perforating gun system for use in a wellbore casing comprising a plurality of perforating banks; said plurality of perforating banks arranged in a cluster, wherein:
- said plurality of perforating banks comprise a first perforating bank and a second perforating bank;
- said first perforating bank comprise a first plurality of charges; said first plurality of charges phased at a first phase angle to each other;
- the first perforating bank having no charges in the same transverse plane;
- said second perforating bank comprise a second plurality of charges; said second plurality of charges phased at a second phase angle to each other;
- the second perforating bank having no charges in the same transverse plane;
- said first phase angle and said second phase angle angularly offset by a first offset phase angle;
- said first phase angle equal to 360 degrees divided by a number of said first plurality of charges; and
- said second phase angle equal to 360 degrees divided by a number of said second plurality of charges.
26. The phased perforating gun system of claim 1 wherein said first plurality of charges are equally spaced and said second plurality of charges are equally spaced.
27. The phased perforating gun system of claim 1 wherein a number of said first plurality of charges range from 2 to 24.
28. The phased perforating gun system of claim 1 wherein a number of said second plurality of charges range from 2 to 24.
29. The phased perforating gun system of claim 1 wherein said first phase angle ranges from 15 to 180 degrees.
30. The phased perforating gun system of claim 1 wherein said second phase angle ranges from 15 to 180 degrees.
Type: Application
Filed: Mar 24, 2016
Publication Date: Sep 28, 2017
Applicant: GEODynamics, Inc. (Milsap, TX)
Inventor: John T. Hardesty (Weatherford, TX)
Application Number: 15/080,251