Oilfield Scale Removal by Chelating Agents: An Aminopolycarboxylic Acids Review

Almubarak, Tariq; Ng, Jun Hong; Nasr‐El‐Din, Hisham A.

doi:10.2118/185636-ms

Cited by 35 publications

(26 citation statements)

References 64 publications

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“…The tetraaza macrocycle DOTA (Chart 1) has also been investigated for the dissolution of BaSO 4 . 12 Despite having the highest reported thermodynamic affinity for Ba 2+ in aqueous solution (log K BaL = 11.75), 19–21 DOTA dissolves BaSO 4 less efficiently than DTPA, 22 reflecting the slow metal-binding kinetics of this macrocycle. Collectively, these limitations underscore the need to develop new ligands for Ba 2+ .…”

Section: Introductionmentioning

confidence: 99%

“…The elimination of BaSO 4 scale is achieved by solubilization using chelating agents. − One of the most commonly used chelators is the acyclic ligand DTPA (Chart ). The thermodynamic stabilities of DTPA complexes of the AEs, however, decrease with increasing ionic radius of the metal ion, rendering DTPA a relatively low-affinity ligand for Ba 2+ (log K BaL = 8.78) .…”

Section: Introductionmentioning

confidence: 99%

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Rapid Dissolution of BaSO₄ by Macropa, an 18-Membered Macrocycle with High Affinity for Ba²⁺

2018

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Insoluble BaSO4 scale is a costly and time-consuming problem in the petroleum industry. Clearance of BaSO4-impeded pipelines requires chelating agents that can efficiently bind Ba2+, the largest non-radioactive +2 metal ion. Due to the poor affinity of currently available chelating agents for Ba2+, however, the dissolution of BaSO4 remains inefficient, requiring very basic solutions of ligands. In this study, we investigated three diaza-18-crown-6 macrocycles bearing different pendent arms for the chelation of Ba2+ and assessed their potential for dissolving BaSO4 scale. Remarkably, the bis-picolinate ligand macropa exhibits the highest affinity reported to date for Ba2+ at pH 7.4 (log Kʹ = 10.74), forming a complex of significant kinetic stability with this large metal ion. Furthermore, the BaSO4-dissolution properties of this ligand dramatically surpass those of the state-of-the-art ligands DTPA and DOTA. Using macropa, complete dissolution of a molar equivalent of BaSO4 is reached within 30 min at RT in pH 8 buffer, conditions under which DTPA and DOTA only achieve 40% dissolution of BaSO4. When further applied for the dissolution of natural barite samples, macropa also outperforms DTPA, showing that this ligand is potentially valuable for industrial processes. Collectively, this work demonstrates that macropa is a highly effective chelator for Ba2+ that can be applied for the remediation of BaSO4 scale.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Rapid Dissolution of BaSO₄ by Macropa, an 18-Membered Macrocycle with High Affinity for Ba²⁺

2018

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“…Among these chelating agents ethylenediaminetetraacetic acid (EDTA), hydroxyethyl ethylene diamine triacetic acid (HEDTA), hydroxyethyl iminodiacetic acid (HIDA), diethylenetriamine pentaacetic acid (DTPA), and methylglycinediacetic acid (MGDA) showed successful applications for scale removal in the oil and gas field. However, the high cost, pH optimization, effective concentration, descale exposure time, and thermal stability are considered the most common disadvantages for employing the chelating agents for the scale removal operations [29,44,45].…”

Section: Introductionmentioning

confidence: 99%

Barium Sulfate Scale Removal at Low-Temperature

et al. 2021

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Precipitation of the scale in the oil and gas reservoirs, surface and subsurface equipment, and processing and production facilities is a big problem as it affects petroleum production. The scale precipitations decrease the oil and gas production and cause economical loss. Solving this issue requires an engineering investigation to provide a safe, efficient, and economic solution. Consequently, this study proposed a developed dissolver for barium sulfate scales, where two field-scale samples were collected from different locations. The compositional analysis for scale samples showed that sample 1 is 100% barium sulfate where sample 2 has 97.75% barium sulfate and 2.25% of quartz. The composition of the developed dissolver has diethylenetriamine pentaacetic acid (DTPA) as a chelating agent, oxalic acid, and tannic acids as an activator, nonionic surfactant, and water as the base fluid. The new dissolver was investigated with extensive lab tests to determine the dissolution efficiency, precipitation tendency for the dissolved scale solids, corrosion rate, and fluid-rock interaction. The obtained successful results indicated that the developed dissolver had a dissolution efficiency for two real barium scale samples as the results showed 76.9 and 71.2% at 35°C and 91.3 and 78.4% at 90°C for samples 1 and 2, respectively. The new solution has a great performance compared with common scale dissolvers in the oil field as hydrochloric acid, ethylenediaminetetraacetic acid, and diethylenetriamine pentaacetic acid. The developed dissolver showed a very low precipitation tendency for the scale dissolved solids (1.9 and 3.2% for samples 1 and 2, respectively) under 35°C for 24 hours. Without any additives of corrosion inhibitors, the corrosion rate was 0.001835 g/cm2 at 6.9 MPa and 100°C for 6 hours. Injecting the developed dissolver for damaged sandstone core sample with barite mud by flooding test showed a return permeability of 115%.

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“…Another common scale dissolver is the chelating agents, which are a more environmentally friendly solution, and less corrosive [37]. The most commonly used chelating agents are ethylenediaminetetraacetic acid (EDTA), hydroxyethyl ethylene diamine tetraacetic acid (HEDTA), hydroxyethyl iminodiacetic acid (HIDA), glutamic acid di-acetic acid (GLDA), diethylenetriamine pentaacetic acid (DTPA), nitrilotriacetic acid (NTA), and methylglycinediacetic acid (MGDA).…”

Section: Scale Removalmentioning

confidence: 99%

A Novel Low-Temperature Non-Corrosive Sulfate/Sulfide Scale Dissolver

et al. 2020

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The oil and gas production operations suffer from scale depositions. The scale precipitations have a damaging impact on the reservoir pores, perforations, downhole and completion equipment, pipeline network, wellhead chokes, and surface facilities. Hydrocarbon production possibly decreased because of the scale accumulation in the well tubular, leading to a well plugging, this requires wells to be shut-in in severe cases to perform a clean-out job. Therefore, scale deposition is badly affecting petroleum economics. This research aims to design a scale dissolver with low cost, non-damaging for the well equipment and has a high performance at the field operating conditions. This paper presents a novel non-corrosive dissolver for sulfate and sulfide composite scale in alkaline pH and works at low-temperature conditions. The scale samples were collected from a production platform from different locations. A complete description of the scale samples was performed as X-ray diffraction (XRD) and X-ray fluorescence (XRF). The new scale dissolver was prepared in different concentrations to examine its dissolution efficiency for the scale with time at low temperatures. The experimental design studied the solid to fluid ratio, temperature, solubility time, and dissolution efficiency in order to achieve the optimum and most economic performance of solubility in terms of high dissolution efficiency with the smallest possible amount of scale dissolver. A solubility comparison was performed with other commercial-scale-dissolvers and the corrosion rate was tested. The experimental work results demonstrated the superior performance of the new scale dissolver. The new scale dissolver showed a solubility efficiency of 91.8% at a low temperature of 45 °C and 79% at 35 °C. The new scale dissolver showed a higher solubility ratio for the scale sample than the ethylenediaminetetraacetic acid (EDTA) (20 wt. %), diethylenetriamine pentaacetic acid (DTPA) (20 wt. %), and HCl (10 wt. %). The corrosion rate for the new non-corrosive dissolver was 0.01357 kg/m2 (0.00278 lb./ft²) which was considered a very low rate and non-damaging for the equipment. The low corrosive effect of the new dissolver will save the extra cost of adding the corrosion inhibitors and save the equipment from the damaging effect of the corrosive acids.

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Oilfield Scale Removal by Chelating Agents: An Aminopolycarboxylic Acids Review

Cited by 35 publications

References 64 publications

Rapid Dissolution of BaSO₄ by Macropa, an 18-Membered Macrocycle with High Affinity for Ba²⁺

Rapid Dissolution of BaSO₄ by Macropa, an 18-Membered Macrocycle with High Affinity for Ba²⁺

Barium Sulfate Scale Removal at Low-Temperature

A Novel Low-Temperature Non-Corrosive Sulfate/Sulfide Scale Dissolver

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Oilfield Scale Removal by Chelating Agents: An Aminopolycarboxylic Acids Review

Cited by 35 publications

References 64 publications

Rapid Dissolution of BaSO4 by Macropa, an 18-Membered Macrocycle with High Affinity for Ba2+

Rapid Dissolution of BaSO4 by Macropa, an 18-Membered Macrocycle with High Affinity for Ba2+

Barium Sulfate Scale Removal at Low-Temperature

A Novel Low-Temperature Non-Corrosive Sulfate/Sulfide Scale Dissolver

Contact Info

Product

Resources

About

Rapid Dissolution of BaSO₄ by Macropa, an 18-Membered Macrocycle with High Affinity for Ba²⁺

Rapid Dissolution of BaSO₄ by Macropa, an 18-Membered Macrocycle with High Affinity for Ba²⁺