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"To Dry or Not To Dry" – A Dehydration Discussion
by: Hall, Jim; Martinez, John — Added 6/29/2009 11:30:09 PMGeneral - Gas Lift Topics


Safe and profitable oil production via gas lift can be achieved through a blend of experienced people, quality hardware, and processes that keep the system operating 24/7.

This conversation is directed toward gas lift gas dehydration and the hidden dangers of hydrates and corrosion that can shut down production and/or create unsafe conditions.

Hardware specifications should meet API or ISO industry standards, which apply to valves/mandrels, compressors, and dehydration equipment. Lift gas process specifications require acceptably dry gas (water vapor removed). Yet operating companies do not always implement these standards, so we will review the perils of not adhering to these guidelines.

“Turbo Gas Lift“- Innovative Hybrid Artificial Lift System, New Developments And Initial Test Results
by: Sinko, Mato; Guzovic, Zvonimir; Matijasevic, Branimir; Keglevic, Kresimir; Nizetic, Tomislav — Added 6/28/2009 12:00:00 AMGeneral - Gas Lift Topics


The operative costs of using ordinary continuous gas-lift significantly rise as oil is lifted from greater depths. The reason is that higher and higher amounts of gas must be compressed at bigger and bigger pressures, as depth rises. Furthermore, maximal intake gas pressure and maximal available amount of gas per well defined by surface gas-lift equipment defines maximal possible lifting depth. Consequently, if the fluid level in the well falls below the level of maximal possible lifting depth (defined by gas intake pressure and gas amount), then there arises a need for surface gas-lift equipment redesign, or even the introduction of other artificial lift types. Both situations commonly involve huge capital expenditures, which can be avoided by introducing the turbo lift system on already wells that already use gas-lift.

Furthermore, use of turbo lift causes huge energy savings compared with ordinary continuous gas-lift, especially when the static pressure decreases and the situation of pressure surplus in gas-lift system occurs.

The turbo gas-lift method is based on a combination of mechanical lifting by pump, and lifting by compressed gas (gas-lift). The pump in the turbo lift system is powered by a gas turbine fed by compressed gas, which after it gives turbine power, is used for gas-lift. By using compressed gas in this way, gas it is doing two types of work instead of one, which leads to higher energetic efficiency compared with conventional gas-lift, especially in lifting from big depths.

The turbo gas-lift system is combined with further main parts:
• Gas turbine, fed by compressed gas from the surface.
• The pump for mechanic lifting of fluid up to the above gas-lift valve. The pump is powered by the gas turbine.
• Standard gas-lift equipment which cotains a working gas-lift valve and release gas-lift valves.

Key benefits of turbo gas-lift:
• Increased volumetric efficiency - higher liquid volumes.
• Superior reservoir drawdown - Increased production rate.
• Decreased gas injection requirements.
• Lower energy consumption.
• Prolonged continious gas lift.
• Decreased abandonment pressure.

This work will present “Turbo Gas Lift“ operation principles, initial test results, and further R&D and field test plans.

A Day in the Life of a Gas-Lift Well Analyst
by: Vetter, Dwayne; Dees, Dan; Peacock, Larry — Added 6/1/2008 12:00:00 AMGeneral - Gas Lift Topics


Provided with the latest technology, tools, and training, the Gas-Lift Well Analyst can increase his/her performance and benefit to an organization. The analyst is one of the key links in the day-to-day operation of a Gas-Lift field and proper emphasis should be placed on the position in any company that strives to get the most out of what they have. If this vital position is ignored, the best intentions of any well managed Gas-Lift field will not be as successful as they should be given just a little focus to the staffing needs, tools and training required in this key role.

Once the position of a Gas-Lift Well Analyst has been established, some key basic guidelines for the role and what it should be responsible for are needed to ensure it is clear what the day to day activities for this staff position are and how they fit into the overall organization.

A Status Report on Gas Lift Systems in Beaver Lodge Madison Unit Horizontal Completions
by: Schmidt, Ron; Hill, Garth; Fredrickson, Dale; Hermann, Jeff; Fangmeier, Keith — Added 6/25/2008 12:00:00 AMGeneral - Gas Lift Topics


Horizontal completions provide many artificial lift challenges in the mature Beaver Lodge Madison Unit (BLMU). The Madison formation @ approximately 8400’ is naturally fractured and partially pressure depleted reservoir. BLMU productivity is enhanced 5x-20x of a vertical completion by placement of horizontal drainholes orthogonal to the natural fractures. Presently the following forms of gas lift are utilized in the BLMU:
• Conventional gas lift with IPO valves—Tubing flow & 1200 psi GL system
• Single point injection with orifice— Tubing flow & 1200 psi GL system
• Single point injection with orifice— Tubing flow & 2200 psi GL system
• Single point injection with orifice--Annular flow & 1200 psi GL system
• Intermittent flow—Tubing flow & 1200 psi GL system

A Study of Flow Stability in Gas-Lift Wells Producing from Saturated Reservoirs
by: Fairuzov, Y. V.; Guerrero-Sarabia, SPE I. — Added 4/15/2008 12:00:00 AMGeneral - Gas Lift Topics


A study was performed to investigate flow stability in gas-lift wells producing from saturated reservoirs. Different stability criteria proposed in the literature were compared using a gas-lift stability map. Based on this study, recommendations on the selection of gas-lift stability criteria were developed. Several examples of gas-lift stability map applications are given. It was shown that stability maps enable designers and operators to determine rapidly the effect of gas-lift design parameters and operating conditions on the system stability. Gas-lift stability maps can also be used for training and educational purposes.

Achieving Stability in a Gas-Lifted Well
by: Kallal, Arun — Added 3/2/2009 12:00:00 AMGeneral - Gas Lift Topics


Maintaining an optimized gas lifted production well is one of the challenges in oil field operation. Un-optimized wells can require more lift gas to achieve reasonable stability, fluid loss due to slug flow, affect other producing wells in the same lease, damage to unloading gas lift valves and increased downtime due to frequent slick line work.

This is more significant in wells with tubing pressure sensitive gas lift valves as oppose to the casing pressure sensitive gas lift valves that is more common in industry. Different initiatives tried in the past have ended up with either little or no success in eliminating the tubing surges of wells with historical surging trends.

Albacora Leste Field: Performance of Gas-Lift Applied to Heavy Oils
by: Neto, Salvador — Added 3/31/2009 12:00:00 AMGeneral - Gas Lift Topics


Albacora Leste is a deep water petroleum field located in Campos Basin, Rio de Janeiro, offshore Brazil. The field comprises a total of 32 horizontal wells (17 production wells and 15 injection wells) tied back to a host FPSO platform moored at 1230 m water depth through flexible flowlines and risers in a free hanging configuration. All production wells are satellite and completed to gas lift injection through only one gas-lift mandrel. Oil densities range from 15 to 28 oAPI at water depths increasing from 950 to 1700 ms. Flow assurance strategies follow internal operational procedures to prevent wax deposition, hydrates formation and severe slugging.

One of the main questions regarding the artificial lift design method relies on the application and performance of gas-lift to heavy oils under a deep water scenario.

An ALS Solution to Low Pressure SAGD
by: Hucman, Will — Added 10/26/2008 12:00:00 AMGeneral - Gas Lift Topics


The most common form of recovery used for deeper bitumen deposits in Canada is SAGD. (Steam Assisted Gravity Drain) Trends are toward low pressure SAGD which translates into lower operating costs and improved recoveries. Lower operating pressures require the use an Artificial Lift System (ALS) to attain desired production rates.

Weatherford has developed a technology specifically design to accommodate the challenges of producing low pressure SAGD wells – the Hydraulic Gas Pump (HGP). The HGP is a rodless technology that uses high pressure gas to displace production fluid. The pump has undergone rigorous lab testing and is currently operating in field trials where it has exceeded expectations. Details provided on the HGP would include: an overview of the pump, its operation, development and a review of field trials and results.

Developing a World Class Gas-Lift Management System – A Case History from Petroleum Development Oman
by: Peringod, Chandran; Riyami, Tariq; Clark, James — Added 6/30/2009 12:00:00 AMGeneral - Gas Lift Topics


Petroleum Development Oman (PDO) is the main oil producer in The Sultanate of Oman, and 25% of the company’s production comes from gas-lift. About 700 wells are on continuous gas-lift with varying water cuts up to 95%. Gas-lift started in PDO in early 70’s and PDO has probably one of the longest histories of gas-lifting in the Middle East. Though PDO gas-lift was very well managed historically, most of the activities got embedded in to the routine work flows over the period of decades and this resulted in reduced focus to the technology itself and especially the new developments.

A gas-lift technology focus group (TFG) was formed in late 2006 to address the gaps in technology management. A detailed work plan was made based on the gap analysis and as a result, a massive gas-lift revamping project was undertaken. This consists of the following elements:

? Gas-lift workshop facilities and staffing
? GL material management system
? Well interventions
? Modelling, design, and opti

Downhole Pressure and Temperature Measurement Offshore and on Land
by: Johnson, Mike — Added 3/2/2009 12:00:00 AMGeneral - Gas Lift Topics


Examples of chamber pressure gauges used offshore California and single operator, truck-mounted bottom-hole pressure units used onshore in the US.

Dynamic Simulation
by: Mantecon, Juan Carlos — Added 4/16/2008 12:00:00 AMGeneral - Gas Lift Topics


This presentation discusses the best current approach for implementing dynamic simulation and establishes its potential for evolving as the sole smart design/optimisation process for complex well completions and production systems to increase oil and gas production and optimise wells, pipelines, and facilities design. In the particular case of gas lift systems, Dynamic Simulation is also fundamental for optimising the well’s unloading process (transient). Dynamic simulation of production systems at early stage is essential to identify and understand the key flow assurance issues. It allows better project definition during the concept selection, FEED and detailed design phases. Dynamic simulation of operative production systems should minimize workover intervention and wireline activities, maximize safety, as well as enable operators to optimize, accelerate, and increase the recovery through the life of the well/field.

Dynamic Simulation of Gas-Lift Wells and Systems
by: Mantecon, Juan Carlos; Dunham, Cleon; Tang, Yula — Added 3/31/2009 12:00:00 AMGeneral - Gas Lift Topics


Dynamic simulation can be used at any stage of a field’s life cycle to build a virtual model of a well and/or production system. It can be used to analyze "what if" scenarios and predict results. It can help to understand transient well behavior and determine the optimum process to eliminate or minimize transient problems that cannot be fully analyzed using NODAL® (steady state) analysis techniques. It does not replace NODAL® analysis but fills gaps where steady-sate analysis techniques cannot provide adequate solutions.

One of the relevant areas of application is for gas-lift wells and systems. In particular, it is useful for subsea and deepwater gas-lift wells, where transient issues related to flow assurance, complex wellbore profiles, long flowlines, and risers play a significant roll in gas-lift system design and production optimization.

Field Development Planning Using a Surface to Subsurface Model
by: Gonzalez, Luis; Inda, Antonio — Added 3/29/2009 12:00:00 AMGeneral - Gas Lift Topics


In reservoir development, selection and implementation of artificial lift is one of the key issues which must be considered when planning for the lifetime of the reservoir. There have been numerous studies of artificial lift implementation as a function of reservoir life cycle. The most common objective of such studies is to maximize recovery (reservoir optimization). It is common practice to implement artificial lift once the wells’ production declines significantly (or ceases) due to decreasing reservoir pressure or increasing water cut. Selection of the artificial lift system is often performed for that period of time, and normally is based only on the resulting increase in production rather than on a global technical-economic evaluation.

Gas Lift Challenges for ExxonMobil
by: Johnson, Mike — Added 3/2/2009 12:00:00 AMGeneral - Gas Lift Topics


Examples of significant challenges that ExxonMobil has experienced or expects operating gas-lift in extended reach wells, installing gas-lift equipment and designing dual gas-lifted wells.

Gas Lift Organizations Maximizing Surveillance Success
by: Fernandez, Carlos — Added 7/1/2009 2:30:31 AMGeneral - Gas Lift Topics


As fields mature, an increasing reliance will be placed on artificial lift systems to effectively produce well volumes. As this occurs, it will become critical to ensure that the talent and technology is available to maximize the benefits of these systems. This paper seeks to review ExxonMobil’s experiences within the US Production company in building the talent required to maximize the value from gas lifted wellbores.

This paper will focus on two key topics:

(1) The training required to ensure optimal gas lift system surveillance and
(2) The need for operational expertise across an organization.

At the close of this paper/presentation the ideal organization for gas lift surveillance will be discussed.

Gas Turbine Inlet Air Fogging
by: Mee, Thomas — Added 6/23/2008 12:00:00 AMGeneral - Gas Lift Topics


Inlet air fogging increases the output of gas turbines by up to 20%, depending on ambient conditions. Fogging can eliminate production losses associated with hot-day operation of gas turbines and can give a further power boost by over injecting fog into the compressor, which gives an evaporative inter-cooling effect.

The presentation will show results from inlet air fogging on dual-spool gas turbines used for driving gas-lift compressors. It will also include experience with installing fog systems on a gas-lift platform in the Persian Gulf.

The presentation will be comprehensive but not too technical.

Gas-Lift Dynamic Simulation - Best Practices
by: Carlos, Juan; Mantecon — Added 6/23/2008 12:00:00 AMGeneral - Gas Lift Topics


These guidelines should facilitate oil and gas production companies in the decision making process on when to apply dynamic simulation as a tool. For instance, the unique features and flow assurance requirements of subsea wells and flowlines, along with the high associated capital costs, clearly merit detailed dynamic analysis for design development. Dynamic simulations provide valuable information for savings and reduction of potential problems (risk reduction) during well completions and production system kick-off operations. The knowledge of the minimum flow rates required to clean up the wells will have relevant implications on equipment selection (size) and therefore cost minimization. Furthermore, the ability to predict (what if cases) and be prepared to deal with potential problems not only can save millions of dollars but can minimise any environmental impact.

Gas-Lift for Steam Assisted Gravity Drainage (SAGD) Developments
by: Noonan, Shauna — Added 6/25/2008 12:00:00 AMGeneral - Gas Lift Topics


The heavy oil recovery method by steam-assisted gravity drainage (SAGD) has become very prevalent in the Canadian tar sands region. Billions of dollars are being spent on SAGD pilots and commercial developments. SAGD is a thermal recovery method that utilizes twin parallel horizontal wells (one above the other as close as 5 m / 16 ft apart) with steam injected into the top horizontal well and production lifted from the bottom. When steam is injected into the upper wellbore, it creates a "steam chamber" within the surrounding reservoir. The resulting heat transfer lowers the viscosity of the oil near the steam / crude interface and allows it to drain by gravity to the horizontal production well below.

Heavy Oil Gas Lift, Using the Concentric Offset Riser
by: Szucs, Adam; Lim, Frank — Added 6/24/2008 12:00:00 AMGeneral - Gas Lift Topics


The production of heavy oil presents a number of problems to deepwater operators. A combination of high fluid density, hence hydrostatic head, and viscosity in the risers tied back to the floating production vessel limits the oil production rate. The Concentric Offset Riser (COR) offers a solution for convenient provision of riser base gas lift all in a single arrangement. The injection of gas at the riser base mixes with and lightens the oil, and hence enhances the production rate from heavy oil reservoirs.

The COR is a pipe-in-pipe riser system suitable for subsea developments tied back to a floating host vessel. The annular space has many potential uses, one of which is gas lift. The vertical riser is tensioned at the top with a buoyancy tank, and tied back to the production vessel with a flexible jumper. Such systems are being implemented in West Africa.

The paper describes the benefits of implementing the COR design for deepwater heavy oil developments.

Improved Gas Lift Proposed for Hungarian Field
by: Gabor Takacs — Added 10/18/2009 10:26:54 PMGeneral - Gas Lift Topics


Abstract will be available at a later date.

Integrated Workflow for Design and Analysis of Gas-Lifted Wells
by: Chokshi, Rajan; Molotkov, Roman; Zdenkovic, Nick; Stephenson, Greg — Added 6/29/2009 12:00:00 AMGeneral - Gas Lift Topics


In order to design a proper gas-lift system it is important to follow a design workflow, which includes the following steps:

• Identify system capabilities in terms of Absolute Open Flow Potential (AOFP), available injection pressure and maximum lift gas injection rate,
• Validate PVT data to ensure applicability and integrity of fluid property correlations/models,
• Validate gradient correlations by comparing flowing gradient surveys against model calculation results,
• Determine system deliverability (or equilibrium point) using a NODAL or System Analysis approach,
• Determine equilibrium point variance with changing well conditions by running sensitivity against system parameters like water cut, reservoir pressure, productivity index, tubing size, lift gas quantity, injection pressure, or modeling parameters like flow correlations,
• Design a gas-lift installation for a particular (or a set of) equilibrium flow condition(s).
• Ascertain design tolerance against future chan

Lagrangian Transient Two-Phase Flow Simulator for Gas-Lift
by: Choi, Kwon Il; Alves, Ibere Nascentes — Added 4/16/2008 12:00:00 AMGeneral - Gas Lift Topics


Applying the Lagrangian model to simulate transient phenomena in Gas-Lift has proved very successful for studying unloading, instability, optimization and even effective gas-lift valve spacing. Other field operations that have been simulated include shut-in and start over. On the other hand, for showing its realistic and dynamic gas fraction distribution, the simulator has been used also as a good visual gas-lift training program. The presentation of this work includes some sample live simulations addressing main issues relating to Gas-Lift.

Maximizing Net Present Value in Mature Gas Lift Fields
by: Mora, Oscar; Startzman, Richman A.; Saputelli, Luigi; Ribeiro, Lidiana M. N.; Nunes, Joao Otavio L. — Added 6/1/2008 12:00:00 AMGeneral - Gas Lift Topics


Advances in mathematical modeling and real-time monitoring have made it possible to more realistically and accurately simulate and measure the future physical behavior and economic performance of gas lifted oilfields. Mature fields, with installed gas lift facilities (e.g. compressors, flowlines, downhole valves) and reliably calibrated reservoir and facility flow models present a favorable opportunity to apply improved and more general optimization methods.

This paper describes a new approach for optimizing gas lift operations in mature oilfields.

The new approach maximizes Net Present Value by integrating mathematical models that describes the behavior of the reservoir, the behavior of the fluid gathering and gas lift systems, and the future economic performance of the field operating under gas lift.

My Gas-Lift is Successful Because…
by: Hall, Jim — Added 3/31/2009 12:00:00 AMGeneral - Gas Lift Topics


Safe and profitable oil production via gas lift can be achieved through application of an appropriate blend of people, hardware and processes.

The “people” component includes management, technical staff, operations and the organisational structure that defines their relationships. The first requirement is for managers who are informed of the importance of gas lift to achieving production targets and are committed to delivering the resources to support gas lift production levels, present and future. As necessitated by the well and reservoir management process, individual asset technical specialists will be trained and capable in gas-lift technology. An often overlooked, essential part of the team are the Operations staff who operate the wells and facilities, report observations, and perform proposed work programmes…often in difficult conditions.

Successful Implementation of an Integrated Production Network Model for the Heera Field
by: Aggarwal, Pavan; Nadar, Manickam — Added 3/2/2009 12:00:00 AMGeneral - Gas Lift Topics


This presentation describes the successful implementation of an integrated production network model for the Heera field located in the Western offshore region of India. The field produces from 119 well strings, most of them gas-lifted.

The network model was built, history matched and calibrated to actual field data. Based on optimization recommendations from the model, following work has been performed so far:

• Wireline intervention in 17 wells (identified in the initial well modeling phase of the project) has led to well gas lift efficiency improvement, giving a total gain of oil production of 800 BOPD.
• Reallocation of lift gas (increase or decrease) based on model recommendation has led to a gain of 900 BOPD with a simultaneous reduction of lift gas requirement by 6%.
• The well models have now been updated with the new gas-lift and production test data, and the new well performance surfaces have been imported into the network model for further optimization.

The Bubble Breaker
by: Schrama, Erik; Fernandes, Richard — Added 4/14/2008 12:00:00 AMGeneral - Gas Lift Topics


The bubble breaker is an orifice plate that can be installed in a gas lifted or naturally producing well with associated gas to enhance production. By generating intense liquid turbulence the bubble breaker breaks up large bubbles and gas slugs into bubbles smaller than 1 mm. The small bubbles move slower through the liquid and are distributed more homogeneously over the cross section of the production tubing. As a result the small bubbles reduce the hydrostatic head in the well. To generate the turbulence and the small bubbles only a small pressure loss over the bubble breaker is required. If the well is deep enough and the gas-to-liquid ratio is within certain boundaries this results in a net reduction in flowing bottom hole pressure and an increase in production.

The Future of Annular Casing Pressure in the Gulf of Mexico
by: Hoshman, Russell M. — Added 3/31/2009 12:00:00 AMGeneral - Gas Lift Topics


The MMS is reviewing API RP 90, API Recommended Practice, Annular Casing Pressure Management for Offshore Wells, for incorporation into the Code of Federal Regulations.

In addition to incorporating this API standard, regulations have been drafted outlining the casing pressure reporting, records keeping and casing pressure departure request process.

This presentation will cover the key points of API RP 90 and the proposed drafted regulations. It will be specifically pointed out how this recommended practice and the new regulations will affect well producing under gas-lift.

The Use of Dynamic Simulation Techniques in Gas Lift Optimization
by: Mantecon, Juan Carlos — Added 3/2/2009 12:00:00 AMGeneral - Gas Lift Topics


This presentation describes the dynamic simulation techniques and compares them with NODAL analysis. Advantages and disadvantages are discussed and guidelines are established on when to apply steady state NODAL analysis, which is the current standard to analyze gas lift wells, and when to apply dynamic simulation (transient analysis) techniques.
Areas of application include sub sea and deepwater gas lift wells, where, in addition, transient issues as flow assurance play a significant roll on gas lift system design and production optimization. Key design considerations in these type of well completions are also discussed.

The Use of Stability Maps in the Design and Operation Gas-Lift Wells
by: Fairuzov, Y.V.; I. Guerrero, Sarabia, Rojas, A. Figueroa — Added 6/23/2008 12:00:00 AMGeneral - Gas Lift Topics


Continuous flow gas-lift wells are susceptible to hydrodynamic instability (heading), which may cause cyclic variations of the wellhead pressure, and oil and gas flow rates. Gas-lift instability is a cause of many operational problems, for example:

• compressor shutdowns caused by pressure and liquid flow rate surges
• difficulties in the operation of low pressure separators
• excessive gas consumption.

Stability problems in complex multiphase systems can be solved using stability maps. A stability map is a plane (2D) diagram that shows the regions of stable and unstable operation of the system, as well as its operating limits.

In this paper theoretical and experimental stability maps for gas-lift wells are presented. Field testswere conducted to investigate the flow stability in a deep offshore gas-lift well. Different gas-lift stability criteria proposed in the literature are compared.

Turbo Gas Lift-Innovative Hybrid Artificial Lift System
by: Kegleviae, Kresimir — Added 4/15/2008 12:00:00 AMGeneral - Gas Lift Topics


Turbo gas lift method is based on combination of mechanical lifting by pump, and lifting by compressed gas (gas-lift). Pump in turbo lift system is powered by gas turbine fed by same compressed gas, which is after gives turbine power, is used for gas lift. By using compressed gas in such way, gas is doing two works instead of one, which leads to higher energetic efficiency compared with classic gas lift, especially in lifting from big depths.This presentation will show technology fundamentals, recent developments, and results of laboratory tests prior to field trial.

US Gas-Lift Experiences
by: Bane, Rodney — Added 6/24/2008 12:00:00 AMGeneral - Gas Lift Topics


ExxonMobil uses a variety of methods for collecting Gas Lift surveillance data from our onshore and offshore US fields. This presentation will review the three key methods used to collect data, troubleshoot problems, and plan optimizations. The collection of Bottomhole Pressure Data (flowing and static pressures) using company owned and operated wireline units will be discussed. A gas lift troubleshooting process using rotating offshore Gas Lift Technicians will be described. Current and planned use of Automation for Gas Lift operations will be reviewed.