Expandable Liner Hangers: Case Histories

Canadian International Petroleum Conference

2006

Typically, Liner-hanger systems have relied upon the primary cement job to provide sealing of the liner/casing overlap. Liner top packers have been run either integrally with the liner hanger or separately in a second trip. In certain applications, cementing the complete liner or obtaining a primary cement seal at the liner top has not been achievable. In these situations, a liner top packer must be used as the primary seal. In cases where the top of cement is above the overlap but below the hanger, the liner-top packer is used as a back-up seal for the overlap.Almost all liner-top packers are run integrally with the liner hanger and are set through the application of weight applied through the drill-pipe or landing string. The capability of the liner-top packer to seal at the maximum pressures rated requires that sufficient setting force of up to 80,000 lbf be applied through the drill-pipe to the packer mechanism. Recently, work performed in Latin America showed the limitations of this process when used in shallow liner-top installations where the available drill string weight is not available.A secondary tie-back packer design offers a conventional alternative to an integral packer design, but installation of this type of configuration requires at least two extra trips into the wellbore and picking up of a string of large drill collars in order to have capability to supply the significant setting force required.A solution that resolved the problems discussed above was an expandable liner hanger, which allows setting force to be applied locally to the hanger body through hydraulic pressure. The setting force for the packer was measurable and consistent.The expandable liner hanger was used in two subsequent jobs, and all three jobs were successful, saving the operator several days of rig time.The case history discussion and system description presented in this paper will verify the flexibility and integrity of the expandable liner hanger.

Section: The New Solutionmentioning

confidence: 99%

Case Histories: Liner-Completion Difficulties Resolved With Expandable Liner-Top Technology

Canadian International Petroleum Conference

2006

“…The expandable liner hanger provided the step change in technology that appeared to have several major advantages over conventional systems (4,5) . This technology (Figure 2) was capable of successfully running and cementing liners and could provide a gas-tight seal in difficult wellbore situations.…”

Section: Solutionmentioning

confidence: 99%

Liner Completion Difficulties Resolved With Expandable Liner Top Technology

Journal of Canadian Petroleum Technology

2008

Liner top packers, which are run as a standalone unit or integrally with conventional liner hangers, are set through the application of weight applied through the drill pipe or landing string. The capability of the liner top packer to seal at the stated pressures rated for which they are designed requires that a sufficient setting force of up to 355857.7 N (80,000 lbf) be applied through the drill pipe to the packer mechanism. Recently, work performed by an operator in Latin America showed the limitations of this process when used in shallow liner top installations where the available string weight alone to apply a sufficient setting force to the liner top packer is not available. Picking up a string of large drill collars in order to have the capability to supply the significant setting force required was an alternative. However, it was not a preferred option, safety being the main concern, followed by handling time, as was seen on the first well utilizing conventional liner hanger and liner hanger packer technology. The expandable liner hanger (ELH) was developed as a solution to resolve the problem of weight down required to set the liner top and allowing a setting force to be applied to the packer elements locally through the hanger body with the use of hydraulic pressure. The setting force for the packer is measurable and consistent, ensuring that a liner top seal and hang weight is obtainable without requiring weight down. This system contains no moving parts, which makes it possible to function with a drill string. Once deployed in the well, the liner hanger body expands radially through the pressurization of its elastomeric elements, thus, creating a gas-tight seal and achieving zonal isolation. The operator chose to deploy the expandable liner hanger system on two subsequent wells following the initial attempt to utilize a conventional system approach. The ELH installations were successful, saving the operator several days of rig time on each well. The case study discussion and system description presented in this paper will explain the flexibility and integrity of the expandable liner hanger in providing a liner top seal upon setting in a shallow liner top installation. Introduction Historically, problems obtaining a good primary cement job at the top of the liner have been associated with the installation of liners in oil and gas wells. Conventional liner hanger systems have relied upon the primary cement job to provide liner top pressure sealing integrity within the liner/casing overlap. In many wells however, cementing the complete liner and liner lap is often not achievable due to various problems, which include loss of circulation, fluid loss or other wellbore/formation conditions. In cases like these, obtaining a primary cement seal across the liner lap is not obtainable, and a liner top packer must be deployed on a second run to make the primary liner the top seal.

“…4,5,6 Based on the following capabilities, the expandable liner-hanger system appeared to offer the required solutions for the troublesome application:…”

Section: The Expandable Solutionmentioning

confidence: 99%

Expandable Liner Hanger Resolves Sealing Problems and Improves Integrity in Liner Completion Scenarios

Production and Operations Symposium

2007

fax 01-972-952-9435. AbstractConventional liner-hanger systems typically rely upon the primary cement job as the main method of sealing the liner/casing overlap, and liner-top packers are run either integrally with the liner hanger or separately in a second trip. In certain applications, however, cementing the complete liner may not be feasible or obtaining a primary cement seal at the liner top may not be achievable; in these situations, a liner-top packer must be used as the primary seal. In cases where the top of cement is above the overlap but below the hanger, the liner top packer is used as a back-up seal for the overlap.Almost all liner-top packers that are run integrally to the liner hanger are set through the application of weight applied through the drill-pipe or landing string. The capability of the liner-top packer to seal with a single element at the maximum pressure rating requires that a sufficient setting force of up to 100,000 lbf be applied through the drill pipe to the packer mechanism. Work performed in Latin America recently showed the limitations of this process and how shallow linertop installations might not have the string weight to apply a sufficient setting force to the liner-top packer.A conventional alternative to an integral packer design is a secondary tie-back packer, but this alternative requires at least two extra trips into the wellbore and picking up of a string of large drill collars to supply the significant force required.A solution was found that was capable of resolving this problem, and the innovative technology applied will be the focus of this paper. An expandable liner hanger that allows a hydraulic setting force to be applied locally to the hanger was used. The setting force for the packer was measurable and consistent. With the success experienced on the first well, the expandable liner hanger was used in subsequent jobs, and in all of them, the operator saved several days of rig time in addition to experiencing a successful completion.