1. Benefits of Phased Limited Penetration Perforating Systems for Well Abandonment
International Perforating Symposium
Amsterdam
2015
Authored by: James Kinsey
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Introduce Owen Oil Tools as a Member of Core Laboratories in the Production Enhancement Division. Owen Oil Tools is considered a leader in perforating and perforating related products used in the completion and re-completions of oil and gas wells LP
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2. Abstract Summary
Well abandonment and zonal isolation have been previously limited to zero-phased perforating systems and/or section milling
To meet a service company’s well decommissioning challenge, new phased limited penetration perforating systems were designed & developed
Achieved flow area improvements of ~ 80% and over 85% reduction in rig operating cost
This presentation is an in depth analysis of a case study examining the benefits of phased limited penetration systems
These systems operate with inherent shortcomings including less area open to flow and potential impeded cement flow
The area open to flow in the primary string using this new technology showed an ≈80% improvement
over standard uni-phased perforating systems.
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3. Challenge
Use Existing Perforating System
Perforate 9-5/8 in. 53.5# P-110 Inner Casing
The challenge submitted by the oil company involved the following characteristics:
Minimal damage to 13-3/8 in. 72# L-80 Outer Casing
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4. Design Parameters
The following information had to be gathered before development could begin:
8.539 in. running restriction for the perforating zone
400°F (204°C) temperature requirements for the well
0.70 in. average entry hole at 18 SPF shot density for inner casing string
Less than 0.10 in. damage to outer string
The ID of the 9-5/8 in. casing was determined to be the running restriction (8.539 in.)
The temperature requirements indicated that a charge rated for 400° F was required
An entry hole average in the inner string of 0.70 in. was requested
To ensure hydraulic isolation, the operator requested an 18SPF shot density to maximize communication and ensure a consistent cement plug was set in the annulus
Due to uncertainty of casing age and integrity, the requirement was set such that no perforations could damage the outer string more than in.
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5. Single Charge Testing and Results
Limited Entry Perforator
The development testing was separated into two areas: Single Charge Testing and Full System Testing
Single charge testing is a cost effective way to determine performance feasibility
The diagram on the left shows the charge positioned inside the gun with the detonating cord shown in green. Then moving downward we see the clearance from the gun to the inner casing and clearance from the OD of the inner casing to the ID of the outer casing.
0.75 in. Entry Hole Through in.
0.07 in. Damage On in.
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6. Full System Test Setup IPS-2015-22 Centralized Test Setup
The system was tested in two full system scenarios: Centralized and De-Centralized
The first scenario featured the 9.625” completely centralized in the ”
The second scenario featured the 9.625” full de-centralized in the ” assuming no collar offset. This decentralized test ensured the system would function properly regardless of tubular orientation and presented a worst case scenario
It should be noted that these systems are tested in ambient scenarios assuming no hydrostatic pressure behind. The addition of hydrostatic pressure will reduce the amount of damage seen on the witness string casing.
Centralized Test Setup
De-Centralized Test Setup
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7. Full System Test Results
Both the centralized and de-centralized full system testing showed consistent entry holes in the 9-5/8 in. casing and minimal damage to the 13-3/8 in. casing
Both figures shown below are from the decentralized full system test.
The figure on the left shows the 9.625” casing .The developed charge produced a hole size average of 0.75”.
The figure on the right shows damage witnessed on the ID of the ” casing. The ID damage depth average was 0.085”.
Both the area open to flow and damage to the ” casing met or exceeded the design parameters requested by the oil company.
9-5/8 in. Hole Size (0.75 in. Average)
13-3/8 in. Damage (0.085 in. Average)
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8. Client Run The well was deviated less than 60°
The client deployed the full system into the well using finned subs for centralization
Area open to flow verified in retrieved 9-5/8 in. casing
The well was deviated less than 60° from vertical thus reducing the chance for losing centralization due to carrier “sag”
The picture shown was taken on location and featured a section of the 9-5/8 in. casing
The client reported no significant damage to the ID of the 13-3/8 in. casing
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9. Limited Penetration Perforating
Client Run Results
The cement plug was successfully set and the well abandoned according to regulation
Reduced abandonment time by 13 days valued at ~$7.8 million
The results in the table below compare section milling to limited penetration phased perforating:
Abandonment Method
Days to Abandon Well
Est. Rig Cost/ Day
Cost to Abandon
Section Milling
15 Days
$600 K
$9 Million
Limited Penetration Perforating
2 Days
$1.2 Million
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10. Conclusions
Phased limited penetration proved to be exponentially more time and cost effective than existing abandonment methods
This method could be used in a variety of applications regardless of geographic location and well orientation
Critical to develop/test in specific well scenario
The majority of limited penetration charges that are offered throughout the industry are 0° systems that need to be run decentralized
These systems need to be designed and tested in specific well scenarios
There are also systems available (ranging from to 7) for perforating tubulars ranging from to ” OD at multiple shot densities that can be run decentralized in certain circumstances
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11. Questions?