Open Hole Packers Provide Zonal Isolation for High Pressure Acid Stimulation within a Chalk Reservoir

Hazel, Paul; Singh, Hemant; Baardsen, Johnny Johnny; Vasques, Ricardo; Pearcy, Ricky G.; Hannah, N.

doi:10.2118/166391-ms

Cited by 6 publications

(1 citation statement)

References 2 publications

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“…Metal Expandable Openhole Packers -these specially designed openhole packers (Hazel et al 2013) would be positioned in the liner string to provide hydraulic isolation between strategically defined zones, intervals, in the horizontal section. Design requirements called for the packers to provide hydraulic isolation at up to 5,000 psi zone-to-zone differential pressure in openhole sizes up to 10½ in.…”

Section: Figure 2-a Conceptual Drawing Of the Un-cemented Liner Showimentioning

confidence: 99%

Intelligent Completions and Un-Cemented Liners Combine to Provide a Fully Completed Solution with Zonal Isolation in Norway

Kent

Burkhead

Burton

et al. 2013

Day 2 Tue, October 01, 2013

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This paper describes the design, testing, installation, and performance of the first 'fully-completed' well using an intelligent inner completion inside an un-cemented liner with openhole packers for zonal isolation. The well design concept evolved from technical challenges associated with completing long cased and cemented laterals in the mature Ekofisk waterflood. The term 'fully-completed' implies full reservoir access along the pay length for production and high rate matrix acid stimulation using limited entry for fluid diversion within well segments.The paper covers the development and qualification of custom openhole 7⅝ in. liner components that can handle high differential pressures and extreme temperature fluctuations, the marriage of this complex liner with a five zone intelligent completion system, and results from a year of system integration testing. The paper also discusses the strategic placement of both mechanical openhole and inner string packers based on caliper and drilling logs; challenges met and overcome during installation; and a remarkable collection of down-hole gauge data that confirms the performance of each component before, during, and after the stimulation.The Ekofisk field waterflood began in 1987 and continues to date, exceeding expectations for improved oil recovery while mitigating reservoir compaction. As the waterflood matures, new wells are more often found partially water-swept. Limited infrastructure for lifting and handling the high water production has led to increased emphasis on isolating these water-swept intervals. Cased, cemented and perforated completions have traditionally been used for this service. It has become increasingly difficult to execute a successful cement job in longer horizontals with 4,000 ft to 8,000 ft laterals where rotation of the liner is impossible and high effective circulating densities (ECDs) limit rates during cementing. Wide variations in reservoir pore pressures, often in excess of 2,000 psi difference along the lateral, are typical of the Ekofisk chalk and exacerbate the difficulties of cementing. As a result, a new method for zonal isolation has been developed to ensure the success of future infill drilling campaigns.The design and careful planning that went into the fully-completed openhole un-cemented liner strategy resulted in a successful field trial and has proven this solution to be an effective alternative to cemented reservoir liners in long horizontals where zonal isolation is critical. Use of the intelligent well system (IWS) allowed offline acid stimulation without rig, coiledtubing, or wireline intervention. What would have traditionally been a significant water producer, with three water-swept zones totaling nearly 2,000 ft across a 4,000 ft reservoir section, has turned out to be one of the best oil producers in the field with nearly zero water cut. Production results show high productivity with highly negative acidized completion skins.With large investments in intelligent completions to provide zone-specific inflow control ...

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Section: Figure 2-a Conceptual Drawing Of the Un-cemented Liner Showimentioning

confidence: 99%

Intelligent Completions and Un-Cemented Liners Combine to Provide a Fully Completed Solution with Zonal Isolation in Norway

Kent

Burkhead

Burton

et al. 2013

Day 2 Tue, October 01, 2013

View full text Add to dashboard Cite

show abstract

Intelligent Completion Inside Uncemented Liner For Selective High-Rate Carbonate Matrix Acidizing

Kent

Burkhead

Burton

et al. 2014

SPE Drilling &Amp; Completion

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Summary This paper describes the design, testing, installation, and performance of the first fully completed well by use of an intelligent inner completion inside an uncemented liner with openhole packers for zonal isolation. The well-design concept evolved from technical challenges associated with completing long cased-and-cemented laterals in the mature Ekofisk waterflood. The term fully completed implies full reservoir access along the pay length for production and high-rate matrix acid stimulation by use of limited entry for fluid diversion within well segments. The paper covers the development and qualification of custom openhole 7⅝-in.-liner components that can handle high differential pressures and severe temperature fluctuations of 200°F; the marriage of this complex liner with a five-zone intelligent-completion system; and results from 1 year of system-integration testing. The paper also discusses the strategic placement of both mechanical openhole and inner-string packers based on caliper and drilling logs; challenges met and overcome during installation; and comprehensive downhole-gauge data that confirms the performance of each component before, during, and after the stimulation. The Ekofisk field waterflood began in 1987 and continues to date, exceeding expectations for improved oil recovery while mitigating reservoir compaction. As the waterflood matures, new wells are more often found partially water-swept. Limited infrastructure for lifting and handling the high water production has led to increased emphasis on isolating these water-swept intervals. Cased, cemented, and perforated completions have traditionally been used for this service. Effective placement of cement is challenging in horizontals 4,000–8,000 ft in length, where rotation of the liner is not possible and high effective-circulating densities limit rates during cementing. Wide variations in reservoir pore pressures, often in excess of 2,000-psi difference along the lateral, are typical of the Ekofisk chalk and compound the difficulties of cementing. As a result, a new method for zonal isolation has been developed to ensure the success of future infill-drilling campaigns. The design and careful planning that went into the fully completed openhole uncemented-liner strategy resulted in a successful field trial and has proved this solution to be an effective alternative to cemented reservoir liners in long horizontals where zonal isolation is critical. Use of the intelligent-well system (IWS) allowed offline acid stimulation without rig, coiled-tubing, or wireline intervention. What would have traditionally been a significant water producer, with three water-swept zones totaling nearly 2,000 ft across a 4,000-ft reservoir section, has turned out to be one of the best oil producers in the field, with nearly zero water cut. Production results show high productivity with highly negative acidized-completion skins. With large investments in intelligent completions to provide zone-specific inflow control and water shutoff, isolation outside the liner becomes much more important. Over recent years, the Ekofisk wells have illustrated the difficulty of achieving effective cement along lengthy reservoir targets. The openhole fully completed solution combining an accessorized uncemented liner with an inner intelligent-completion string will allow operators to push the limits in terms of lateral length while maintaining full control over producing and nonproducing zones.

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Improved Zonal Isolation in Open Hole Applications

Bardsen¹,

Hazel²,

Vasques³

et al. 2014

All Days

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Achieving effective zonal isolation within long reach horizontal wells via conventional means, such as cement or swell packers, is becoming increasingly challenging to the industry. The longer step outs limit the Equivalent Circulation Density (ECD) due to frac/pore pressure limitations. Subsequent complex stimulation operations impose higher differential pressure (dP) across the packers. To address these challenges, a novel design was introduced, effectively creating an expandable metal, sleeve-type annular barrier that allows cementless completions and effective zonal isolation. The design of the new annular barriers, assembled on a full bore liner, minimizes the running outside diameter (OD) whilst delivering a high differential pressure seal even within a washed out hole. The qualification process was designed to meet the International Organization for Standardization ISO14310 V3 standard and to simulate the lifecycle of the packer during acid stimulation and later-life water management. The benefits to operators include increased reliability and certainty for success, both in the short-term and over the life of the wells. This paper reports recent implementation of the new annular barrier to meet the unique challenges of annular high pressure containment. Findings are supported by specific case examples, and the paper includes a discussion on design, application and performance.

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Open Hole Packers Provide Zonal Isolation for High Pressure Acid Stimulation within a Chalk Reservoir

Cited by 6 publications

References 2 publications

Intelligent Completions and Un-Cemented Liners Combine to Provide a Fully Completed Solution with Zonal Isolation in Norway

Intelligent Completions and Un-Cemented Liners Combine to Provide a Fully Completed Solution with Zonal Isolation in Norway

Intelligent Completion Inside Uncemented Liner For Selective High-Rate Carbonate Matrix Acidizing

Improved Zonal Isolation in Open Hole Applications

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