Successful Closure of Zonal Sand Production with Silica Gel in a Horizontal Well

Agerbaek, Mikkal; Gregersen, Søren; Eriksen, Katrine; Noer, Jesper; Mulrooney, Mark Joseph

doi:10.2118/145397-ms

Cited by 4 publications

(2 citation statements)

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“…Some of the sodium silicate gels are relatively brittle and compared to organic gels they are more easily degraded by high pressure gradients. However, a recent work on the development on sodium silicate systems by Agerbaek et al (2011) has indicated that silicate gels also can produce high tensile strengths. The sodium silicate is commercially available as concentrated liquid, with SiO 2 concentration of approximately 30%, which upon dilution in soft brine produces a stable solution with water-like viscosity.…”

Section: Introductionmentioning

confidence: 99%

Snorre In-Depth Water Diversion - New Operational Concept for Large Scale Chemical Injection from a Shuttle Tanker

Skrettingland

Ulland

Ravndal

et al. 2016

SPE Improved Oil Recovery Conference

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Declining oil production and increasing water cut in mature fields highlight the need for improved conformance control. Here we report on a successful in-depth water diversion treatment using sodium silicate to increase oil recovery at the Snorre field, offshore Norway, utilizing a new operational concept of using a stimulation vessel as a platform for the large-scale injection into a subsea well. A custom modified 35,000 DWT shuttle tanker was employed for the field pilot. This paper describes the vessel preparations and the large-scale interwell silicate injection operation. The operational aspects of the large-scale interwell silicate injection include; identification of injection vessel requirements, major vessel modifications, chemical logistic, general logistics to site, major equipment set-up on vessel, subsea connection, mixing and pumping schedules, onsite QC, and real time monitoring. Experience from these operations and lessons learned are included in this paper.After the injection of approximately 400,000 Sm 3 (113,000 Sm 3 preflush, followed by 240,000 Sm 3 of sodium silicate gelant and 49,000 Sm 3 of postflush fluid) at injection rates up to 4,000 Sm 3 /d, the injection from the vessel was stopped and the well was put on regular seawater injection. Following more than two years of regular production, transient pressure measurements, tracer testing and water cut data are presented from the ongoing comprehensive data acquisition program. These results demonstrate clearly the achieved in-depth flow diversion through a delayed breakthrough of injected tracers and lower water cut in the relevant production well.

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Section: Introductionmentioning

confidence: 99%

Snorre In-Depth Water Diversion - New Operational Concept for Large Scale Chemical Injection from a Shuttle Tanker

Skrettingland

Ulland

Ravndal

et al. 2016

SPE Improved Oil Recovery Conference

View full text Add to dashboard Cite

show abstract

“…Some of the sodium silicate gels are relatively brittle and compared to organic gels they are more easily degraded by high pressure gradients. However, recent work on development on sodium silicate systems by Agerbaek et al (2011) has indicated that silicate gels can produce high tensile strengths. Sodium silicate is also known from alkaline EOR flood.…”

Section: Introductionmentioning

confidence: 99%

Snorre In-depth Water Diversion Using Sodium Silicate - Large Scale Interwell Field Pilot

et al. 2014

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Here we report on in-depth water diversion using sodium silicate to increase oil recovery at the Snorre field, offshore Norway. A comprehensive qualification program revealed that the onset of gelation can be controlled; this was demonstrated in realistic core flood experiments as well as in a single well injection pilot. This paper highlights key design, response measurement plan and operational experiences from a large scale interwell field pilot of sodium silicate injection in a reservoir segment at the Snorre field on the Norwegian Continental Shelf. The operation of injecting 113 000 m 3 preflush, 240 000 m 3 sodium silicate and 49 000 m 3 postflush was performed from June to October 2013. The goal is to create an in-depth restriction between a subsea water injection well and a platform oil producer with approximately 2 000 m well spacing, and thereby improve the reservoir sweep by water injection.To perform the field pilot a 35 000 ton shuttle tanker was converted to a well stimulation vessel with the necessary equipment to accommodate a higher number of people, a desalination plant, storage and mixing equipment and high pressure pumps. The vessel was connected directly to a subsea water injection well and injected during a period of 5 months. The chosen design was to (a) soften the formation water by a KCl preflush, (b) control the gelation kinetics using HCl acid as activator, mixed into the diluted silicate solution and (c) displace the silicate solution by a KCl postflush followed by seawater injection.The pilot injection operation is completed, and the displacement of the sodium silicate with following seawater injection to the planned position for in-depth plugging is still on-going. The operational success criteria of proving ability to perform large scale transport, mixing and injection of sodium silicate from a shuttle tanker directly into a subsea well with no near wellbore plugging is met. Future production response will reveal if the success criteria of in-depth plugging, improved reservoir sweep and decrease in water cut will be met.

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Application of Micro-fine Cement for the Sequential Zonal Abandonment of a Multi-Zone Sand Propped Fractured Horizontal Well With Coiled Tubing - Lab Studies, Field Trial & Computational Fluid Dynamics

Boekholtz

Bansal

Pasturel

et al. 2014

Abu Dhabi International Petroleum Exhibition and Conference

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For the first time in a Danish field, micro-fine cement was used to abandon a multi-zone horizontal well by plugging each sand fractured zone sequentially. Lab testing was performed to investigate the depth of penetration of different conformance systems in a 20/40 sand pack. The micro-fine cement showed the highest penetration and was considered the best option for abandoning sand propped fracs in horizontal wells. The first field application was unsuccessful due to pre-setting of the micro-fine cement in the Coiled Tubing. Extensive lab tests were performed to understand the causes of the pre-mature setting of the cement. A new cement recipe was selected and subjected to modified lab test procedures to successfully abandon the horizontal well. To economically develop chalk reservoirs in the North Sea, long horizontal wells are drilled, hydraulically fractured and waterflooding is applied to the field. To ensure conformance, flow from each fracture is controlled by a Sliding Side Door (SSD). Well A suffered injection water breakthrough which could not be controlled by closing the SSDs. To enable the full abandonment of each zone the decision was made to isolate each zone sequentially from the toe of the well up with cement retainers and to use Coiled Tubing to squeeze a pre-determined volume of special micro fine cement into the zone in order to plug the tubing, the tubing-liner annulus, any cement channels and a limited section of the sand propped fracture. In this manner any potential water channeling between zones and with other wells in the pattern would be prevented. This paper discusses the results of initial lab tests, causes of failure of the first job, testing of new micro-fine cement and the successful application. This paper also discusses the results of computational fluid dynamics simulations which were performed to understand the behavior of cement in a fracture and enable further improvements to similar abandonments in the future.

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Successful Closure of Zonal Sand Production with Silica Gel in a Horizontal Well

Cited by 4 publications

References 0 publications

Snorre In-Depth Water Diversion - New Operational Concept for Large Scale Chemical Injection from a Shuttle Tanker

Snorre In-Depth Water Diversion - New Operational Concept for Large Scale Chemical Injection from a Shuttle Tanker

Snorre In-depth Water Diversion Using Sodium Silicate - Large Scale Interwell Field Pilot

Application of Micro-fine Cement for the Sequential Zonal Abandonment of a Multi-Zone Sand Propped Fractured Horizontal Well With Coiled Tubing - Lab Studies, Field Trial & Computational Fluid Dynamics

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