ALRDC Technical Library

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Gas-Lift Valve and Gas-Lift Mandrel Metallurgy, Welding, and Testing
by: Holt, Jim — Added 6/25/2008 12:00:00 AMFluid

Gas-Lift Mandrels and Gas-Lift Valves are being exposed to service conditions today that require careful selection of materials and processes. This presentation is to review standard selected materials mostly used in the industry for specific service conditions. Discussions will include materials strength, corrosion resistance and conditions suitable for service conditions.

Mandrels and gas lift valves are an assembly of many components. To complete the assembly of these products requires fabrication processes which includes welding and brazing processes. Discussions for typical fabrications and processes will be discussed.

Any time there are fabrication processes used, there needs to be inspection methods at hand to verify the quality of those processes being preformed. A brief review of those inspection methods will be discussed in this presentation.

A High-Reliability Gas-Lift Orifice
by: Hall, Jim — Added 4/14/2008 12:00:00 AMFluid

The High Reliability gas-lift Orifice (HrglO) was conceived to address a $1MM hard cost associated with a tubing leak tracked down to a $2000 leaking reverse flow valve in a gas lift orifice. A short brainstorming session produced several approaches which were then reviewed and ranked according to development time, cost and compatibility with existing hardware. A patent search produced a similar design to one of the concepts, but the maintenance payments on the patent had been stopped and so the intellectual property was in the public domain.

A New Approach to Describe the Gas Throughput Capacity of Gas Lift Valves
by: Turzo, Z., Takacs, Gabor — Added 10/18/2009 9:21:50 PMFluid

Abstract will be available at a later time.

by: Ken Decker, Cleon Dunham, Burney Waring — Added 6/10/2009 4:16:13 PMFluid

This paper presents the practice of using downstream chokes in unloading injection pressure operated (IPO) gas-lift valves. The practice helps to assure effective unloading and may provide protection against erosion damage during the unloading process. It has several other benefits that are discussed in the paper.

A gas-lift valve/choke model has been developed. It provides accurate predictions of the gas passage through the choked valve during the unloading process. And, it can help to analyze existing gas-lift performance, where the objective is to determine which valve(s) are open and how much gas is being injected through them. This model is described in the paper.

Application of Surface-Controlled Gas-Lift Valves For Natural Gas Cap Lift On BHPB Lennox Field
by: Lovie, Eric; Burke, Kevin — Added 6/23/2008 12:00:00 AMFluid

The Lennox field is situated 5 km off the English west coast, part of BHP Billiton’s Liverpool Bay Development in the Irish Sea.

A combination of increasing facilities back-pressure, decreasing reservoir pressure and increasing watercut prevented some of the wells from restarting after shut-in. Coiled tubing intervention was used to kick off such wells but the small unmanned platform meant that this process could only be performed on a campaign basis rather than as normal production operations, resulting in reduced oil recovery.

The solution to overcome these problems was to use the natural gas cap of the reservoir to provide lift. A surface controlled gas lift valve, the Schlumberger WRFC-H (Wireline Retrievable Flow Controller - Hydraulic) was installed in each well and it’s variable choke utilized to provide control of gas from the reservoir. Once the oil layer has been depleted the WRFC-H can be opened fully, converting the well to gas production.

Effect of Operating Valve Performance on Stability of Gas-Lift Wells
by: Fairuzov, Y.V.; I. Guerrero, Sarabia — Added 6/23/2008 12:00:00 AMFluid

In this paper, the effect of operating valve design on gas-lift stability is studied. It is shown that the gas-lift stability maps proposed in an earlier study may facilitate the selection of the operating valve design. Different valve designs are considered: the conventional orifice and gas-lift valves, as well as the nozzle-venturi valve. Gas-lift stability maps are constructed for each operating valve design. Advantages and disadvantages of the considered valve types are discussed from the point of view of the gas-lift stability. Based on the comparison of the gas-lift stability maps, recommendations on the selection of the operation valve type are elaborated.

Erosion Effects on Gas Lift Valves in Well Discharge Operations
by: Ribeiro, P. J. P.; Lima, F. S. — Added 6/29/2009 12:00:00 AMFluid

This work presents results of a series of tests performed in a field scale laboratory focusing on erosion effects on gas-lift valves in well discharge operations. A test facility was assembled to allow the flow at different flow rates of completion fluid through valves mounted inside a test mandrel. Valves were inspected and checked for performance before and after running completion fluid through them.

Experiments were performed with commercially available orifices, venturi, and pressure valves. Results suggest that erosional damage may occur even at speeds of 1 bbl/minute in the tested valves; a value usually considered in standards and by the industry as safe for preventing erosion. These results show the need for efforts toward the development of valves able to resist erosion at high rates of completion fluid discharge, mostly for sub-sea applications, where well workover equipment is of limited availability and high cost.

Gas-Lift Bellows
by: Isham, Doug — Added 6/25/2008 12:00:00 AMFluid

We manufacture gas-lift bellows beginning with seam-welding of the three tubes or plies. Additional processing brings the tubes to their final wall thickness. The tubes are telescoped together to make the three plies. The tubes are then mechanically bulge formed which starts the formation of the corrugations. A roll forming process (a mechanical spin and roll form process using grooving dies and an arbor) is done until the bellows come into final dimension specification. Final form also now defines the bellows functional characteristics. The bellows are then circumferentially circle welded to seal the plies together to make them leak proof. Units are Vacuum leak tested to detect bad product and inspected for dimensional conformity.

Gas-Lift Orifice Valve – Safelift
by: Kleppa, Erling — Added 3/31/2009 12:00:00 AMFluid

In close cooperation with Statoil, Petroleum Technology Company AS (PTC) developed a gas lift orifice valve - Safelift - with the primary purpose of being qualified as a valve barrier with leakage requirements related to ISO 14310-V1 or better.

The valve was tested and qualified to the new ISO-17078-2, ISO-14310-V1 as well as additional and even more stringent Statoil criteria in a special validation test program.

In combination with PTC's hydraulic surface annulus valve (H-SAS), which is a gas injection valve installed in the VR profile in the production tree's unihead. The H-SAS is qualified to the ISO 10423 (API 6A) standard, thus provides two independent and extremely effective well barriers for the A-annulus. With this effective artificial lift is achieved without compromising the globally recognised barrier envelopes for producing wells.

Gas-Lift Valve Temperature Distribution: Theoretical and Experimental Analysis
by: Ganzarolli, Marcelo; Altemani, Carlos Alberto; Almeida, Alcino Resende — Added 5/22/2008 12:00:00 AMFluid

Retrievable gas-lift valves (GLV) like the Camco R-20 have a nitrogen-charged dome acting on the GLV bellows. This pressure is counterbalanced by the injection gas pressure to control the GLV operation. The nitrogen temperature affects the pressure and depends on both the well fluid and the injection gas temperatures. The purpose of this work was to investigate this dependence for a GLV in a side pocket mandrel.

Initially a compact thermal model was developed to estimate the thermal resistances from the dome to the other parts of the GLV. The results of this investigation indicated that the axial resistance along the GLV body was much larger than the radial resistance from the dome to the mandrel tube. This model was based on heat transfer correlations and approximations, and its conclusions needed verification by experiments.

High Reliability Gas Lift Flow Control Devices Increase Well Safety and Reduce Well Intervention Frequency
by: Xu, Jun; Hall, Jim; Franke, William; Pastor, Guillermo; Ghobrial, Nora; Breaux, Ashby; Hunt, Tommy — Added 3/31/2009 12:00:00 AMFluid

A family of high reliability gas-lift flow control devices has been developed for use offshore Gulf of Mexico where regulatory requirement and risk are much higher than in other parts of the world. The technology provides a primary safety barrier between the tubing and casing for sour service and reduces wellbore intervention frequency for deepwater (Tension Leg Platform and subsea) wells.

This Shell patented technology uses a flow tube and a flapper as the primary flowing and sealing mechanism. The deliverables of the technology comprise an externally mounted check valve for use on the inlet of specially designed gas-lift mandrel, orifice (operating valve) and unloading valve. A series of tests, a qualification program, and modeling have been conducted to validate that the high reliability gas-lift control devices meet the test standard and acceptance criteria.

Use of Gas-lift valve Dynamic Performance Data in Optimizing Well Gas-Lift Designs
by: Nadar, Manickam S. — Added 3/2/2009 12:00:00 AMFluid

Designing gas-lift unloading strings for gas lifted producers often throws many challenges, one of them being the knowledge of how an unloading valve will function under the dynamic conditions downhole. The dynamic tests performed on gas lift valves have indicated that many factors related to the valve construction affect the valve performance to a significant extent and that using the Thornhill Craver model for gas passage calculations for unloading valves could be misleading.
Knowing the valve performance behavior under varying upstream and downstream pressures and temperatures has helped improve gas lift designs. This is of significant importance where production pressure operated (PPO) valves are used for gas lift unloading designs, as the valve performance is a critical issue with these designs.

Using Valve Performance in Gas-Lift Design Software
by: Tom Nations — Added 6/28/2009 12:00:00 AMFluid

This presentation includes a discussion of how Valve Performance can be incorporated into and used in a gas lift design software package.

This presentation will attempt to:

- Define valve performance.
- Describe the differences between some of the current valve performance correlations.
- Discuss valve performance availability in various gas-lift design software programs
- Illustrate how valve performance can aid in gas-lift design.
- Show what can happen if valve performance is not considered.

When Wireline Won’t Work:Coil Tubing Gas-Lift Valve Retrieval
by: Fernandez, Carlos — Added 3/31/2009 12:00:00 AMFluid

As highly deviated, complex wells become more common in offshore oil production it is expected that the use of unconventional methods (coil tubing, wireline tractors, etc.) for gas-lift valve retrieval and setting will increase across the industry. This paper review ExxonMobil’s experiences utilizing wireline and coil tubing for gas-lift valve retrieval and setting in highly deviated wells. A detailed case study will be presented on a successful retrieval made at the Heritage field (Santa Ynez Unit) in California. At the close of this paper/presentation a discussion of ideal wellbore configurations to optimize future coil tubing interventions will be included based on ExxonMobil experience.