One-Step Acid Removal of an Invert Emulsion

Quintero, Lirio; Jones, Tom; Clark, David

doi:10.2523/94604-ms

Cited by 19 publications

(4 citation statements)

References 10 publications

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“…In order to evaluate the NCW removal performance, the results were compared with three different studies that investigated removal solutions of filter cakes generated by oil-based mud with calcium carbonate as a weighting material, [46], [47] and [34]. Table 2 shows the filter cake removal efficiency, the retained permeability on sandstone cores, and the corrosion generated by the cleaning fluid for the aforementioned studies and for the proposed one.…”

Section: Results Comparison With Similar Studiesmentioning

confidence: 99%

“…Quintero et al [46] investigated the use of micro-emulsion on OBDFs' filter cake removal. The investigated single-phase micro-emulsion (SPME) consists of water, solvent and surfactant diluted in calcium chloride brine.…”

Section: Introductionmentioning

confidence: 99%

“…The procedure followed for the treatment design includes a solubility test for calcium carbonate particles in a novel cake washer (NCW) at different conditions, such as duration, temperature and acid concentration, a corrosion test of the actual casing joint at HPHT, and filter cake removal efficiency at 212 • F and 300 psi, and retained permeability on a ceramic disc and Berea sandstone core sample. NCW removal performance was compared with different studies that investigated removal solutions for filter cakes generated by OBDF with calcium carbonate as a weighted material [34,46,47]. The comparison against the presented study was conducted based on the filter cake removal efficiency, the retained permeability and the corrosion rate generated by the cleaning fluid, as possible.…”

Section: Introductionmentioning

confidence: 99%

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Novel Cake Washer for Removing Oil-Based Calcium Carbonate Filter Cake in Horizontal Wells

et al. 2020

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An impermeable layer “filter cake” usually forms during the overbalanced drilling technique. Even though it helps in protecting the formation from a further invasion of drilling fluids, the removal of this layer is essential for a proper cement job and to avoid any reduction in wellbore deliverability. The design of the removal process is complicated and depends on the filter cake composition and homogeneity. This paper presents an experimental evaluation on the usage of a novel cake washer (NCW) in the removal of a filter cake formed by an invert emulsion oil-based drilling fluid that contains calcium carbonate as a weighting material while drilling a horizontal reservoir. The proposed NCW is a mixture of organic acid, mutual solvent and nonionic surfactant. It is designed to enable restored wellbore permeability for a sustainable production. Since the filter cake mainly consists of the weighting material, the solubility of calcium carbonate in NCW at different ranges of temperature, duration and concentration was investigated. An actual casing joint was used to test the corrosion possibility of the treating solution. High-pressure and high-temperature (HPHT) filtration tests on ceramic discs and Berea sandstone core samples were conducted to measure the efficiency of the filter cake removal and the retained permeability. Ethylene glycol mono butyl ether (EGMBE) was used as a mutual solvent and the solubility was higher compared to when the mutual solvent was not used in the washer formulation. A significant increase in calcium carbonate dissolution with time was observed for a duration of 24 h. The solubility was found to be proportional to the concentration of NCW with optimum results of 99% removal at a temperature of around 212 °F. At those conditions, no major corrosion problems were detected. Permeability of the core retained its pristine value after the treatment.

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Section: Results Comparison With Similar Studiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Novel Cake Washer for Removing Oil-Based Calcium Carbonate Filter Cake in Horizontal Wells

et al. 2020

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“…A microemulsion is a very stable homogenous fluid that was formulated by adding alcohol to surfactant-stabilized oil in water emulsions [20]. It can be used to dissolve the filter cake of synthetic and oil-based filter cakes in open-hole completions [21].…”

Section: Introductionmentioning

confidence: 99%

One-Stage Calcium Carbonate Oil-Based Filter Cake Removal Using a New Biodegradable Acid System

Elkatatny

2019

Sustainability

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Removal of the oil-based filter cake is a complex task especially in horizontal and multilateral wells. The presence of oil makes the removal process more challenging because the oil coats the weighting materials and prevents acid-filter cake interaction. Therefore, different additives are required to change the wettability of the filter cake to enhance the removal efficiency. This paper introduces a new biodegradable acid system (NBAS) that can efficiently remove oil-based filter cake in horizontal and multilateral wells where calcium carbonate is used as a weighting agent. The new biodegradable acid system (NBAS) consists of 50 vol.% biodegradable acid and 5 vol.% mutual solvent, and the remaining percent is deionized water. High-pressure high-temperature (HPHT) filtration experiments were performed to evaluate the filter cake removal efficiency and the retained permeability. The filtration and removal experiments were conducted using real core samples (Indiana limestone and Berea sandstone) at a temperature of 212 • F and 300 psi differential pressure. Afterward, the NBAS was evaluated by measuring physical properties and conducting corrosion, compatibility, and thermal stability studies. The obtained results showed that the NBAS was compatible and thermally stable for more than 48 h at 212 • F and 300 psi. The NBAS has a density of 1.05 g/cm 3 , viscosity of 1.47 cP, and surface tension of 32 dynes/cm at room temperature. The corrosion rate of the developed system was 0.03 lb/ft 2 , which is acceptable according to oil and gas industry best practices. Removal experiments showed that the filter cake was completely removed from the core samples. For Berea sandstone, 100% of the permeability was regained, while the retained permeability for Indiana limestone was 122.5%, confirming the complete removal of external and internal filter cake as well as core samples stimulation. The new acid system can be considered as an efficient solution for oil-based filter cake removal that is biodegradable and cost-effective, where the reservoir permeability can be regained in one-stage only.

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First Application of Novel Microemulsion Technology for Sand Control Remediation Operations—A Successful Case History from the Rosa Field, a Deepwater Development Project in Angola

Lavoix

Jones

Quintero

et al. 2007

European Formation Damage Conference

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This paper documents a novel engineering approach and the operational methodology used to achieve high efficiency remediation on two offshore applications. Results are presented, detailing specific placement procedures, in-situ treatment design and productivity improvements. Two wells were recently drilled and completed for the Rosa deepwater project, Block 17 offshore Angola, using a Non-Aromatic Oil-Based Mud (NAOBM) weighted with sized calcium carbonate. After installing the Stand-Alone-Screens (SAS) across the production intervals and allowing the wells to cleanup, the Productivity Index (PI) measured on each well was very disappointing. A diagnosis study concluded that the severe productivity impairment on these wells was related to either screen plugging by mud particles while running the screens to bottom in the NAOBM and/or the plugging induced by a mixture of formation sand, mud, and filter cake when draw-down was applied during cleanups. Based on collaborative laboratory work between the operator and a service company to design a treatment fluid for removing NAOBM filter cake material for water injection wells, a microemulsion spotting fluid was formulated to remediate the damage in the two Rosa wells. The formulation contains a surfactants blend, acetic acid, and brine. The remediation was performed using a Coiled Tubing (CT) equipped with a rotating jet blaster to spot the treatment fluid inside the screen assemblies. Each treatment was allowed to soak. After the placement of the treatment pills on each well, cleanup measurements indicated significant PI improvements close to expected values. Production Logging Tests (PLT) analysis indicates that both wells are producing from almost all screen lengths. Despite the challenging placement of the treatment fluid in the SAS assembly, the diffusion of the microemulsion with acid allowed break up and removal of blocking solids from the completion screens and filter cake residues from the wellbore walls, allowing full production. Introduction The Rosa field was discovered in January 1998 with the Rosa 1 well and was appraised with two additional wells at the beginning of year 1999 and at the end of 2000. The field is located in Block 17, offshore Angola, 210 km northwest of Luanda, in average water depth of 1,400 m (Fig. 1). Rosa field is one of several fields in this prolific block. Under a production sharing agreement with Sociedade Nacional de CombustÍveis de Angola (SONANGOL), the Angolan state oil company, partners in the field include Total E&P Angola (40%, operator), Esso Exploration Angola (Block 17) Ltd (20%), BP Exploration (Angola) Ltd (16.7%), Statoil Angola Block 17 A.S (13.3%), and Norsk Hydro Dezassete A.S. (10%). After analysing several development options, the solution chosen was subsea development and connection of the field (tie-back) via subsea pipelines to the Girassol Floating Production Storage and Offloading (FPSO) unit located at a distance of between 15 and 20 km from Rosa, with new installations on the FPSO unit for processing the production from Rosa (Fig. 2). The adopted development scheme includes the drilling, in the base case, of 25 wells (14 production wells and 11 water injection wells). Production from the Rosa site is scheduled to begin during the 2nd quarter 2007. All reservoirs in this field are constituted of highly unconsolidated sands, which require the wells to be completed with sand-control techniques. The wells have high productivity, up to 30,000 Barrels of Oil Per Day (BOPD), because of the excellent reservoir characteristics. Pressure maintenance of the field is achieved with seawater injection. Field Geologic and Reservoir Description The Rosa Upper Oligocene structure is constituted of Rosa D and Rosa E main channels above the Rosa D West secondary channel. The Upper Oligocene corresponds to the deposition of turbidites along NE-SW channelized systems within this NW-SE basin between peripheral salt ridges.

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One-Step Acid Removal of an Invert Emulsion

Cited by 19 publications

References 10 publications

Novel Cake Washer for Removing Oil-Based Calcium Carbonate Filter Cake in Horizontal Wells

Novel Cake Washer for Removing Oil-Based Calcium Carbonate Filter Cake in Horizontal Wells

One-Stage Calcium Carbonate Oil-Based Filter Cake Removal Using a New Biodegradable Acid System

First Application of Novel Microemulsion Technology for Sand Control Remediation Operations—A Successful Case History from the Rosa Field, a Deepwater Development Project in Angola

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