Additive Scale Removal Based on Noncorrosive Organic Acid for Handling Silica and Carbonate Scale in Oil and Gas and Geothermal Wells

2021 ◽  
Author(s):  
Usman Pasarai ◽  
Panca Wahyudi S. ◽  
Arie Haans ◽  
IGN Widiantara ◽  
Budi Saroyo
Keyword(s):  
Organic Acid ◽  
Oil And Gas ◽  
Reduction Rate ◽  
Production Capacity ◽  
Environmentally Friendly ◽  
Xrd Analysis ◽  
Production Equipment ◽  
Good Effect ◽  
Acid System ◽  
Dissolution Efficiency

Abstract The silica and carbonate scale that forms along the production pipeline is a significant problem in the oil and gas and geothermal industry because it disrupts production operations. Silica and carbonate scales on the inside of the pipe cause blockage of flow and an increase in pressure. Failure of downhole settlement equipment will reduce the production capacity of the well, and the maintenance burden will increase. The main objective of this research is to test the reactivity of an environmentally friendly non-corrosive organic acid system based on vegetable fatty acids and carbohydrates with high dissolution efficiency for the treatment of silica and carbonate scales in geothermal and oil and gas fields. This paper provides information on laboratory analysis in terms of analysis of the composition of scale samples obtained through XRD analysis, acid system developed testing for dissolution efficiency at 50°C and 100°C for 1 hour, compatibility and stability testing, and testing the corrosive impact on coupon metal AISI CS-1019 samples at 100°C for seven days in a closed aging cell. Testing the concentration of the new organic acid system in high dissolution efficiency and low corrosion effect was carried out through laboratory-scale studies before being applied to field-scale operations. The results showed that the dissolution efficiency of the scale sample against the developed organic acid system (100% concentration) at 50 and 100°C for 1 hour showed reactive effect. Reduction rate of silicate-07; silicate-29; silicate-L1; silicate-KB1; carbonate-A3 at 50°C were 7.825%; 3.823%; 6.177%; 2.014%; 8.211%, and at 100°C were 12.884%; 0.631%; 15.047%; 0.103%; and 32.909%. The newly developed organic acid system demonstrates stability and compatibility with formation waters with low formed solids, and it has a pH of 6. The results of the corrosion rate test were carried out without an inhibitor at 100°C for seven days and gave a yield of 77.340 mils per year, while other commercial additives gave a yield of 2,525.120 mils per year. The new eco-friendly organic acid system has a good effect in helping dissolve silica and carbonate scales, safe for production equipment, and lowers high maintenance costs. Keywords: Organic Acid Scale Remover, Silica and Carbonate Scale, Environmentally friendly

Dissolution of Sulfates and Sulfides Field Scales by Developed Scale Dissolver

2021 ◽  
Author(s):  
Hany Gamal ◽  
Salaheldin Elkatatny ◽  
Dhafer Al Shehri ◽  
Mohamed Bahgat
Keyword(s):  
Oil And Gas ◽  
Flow Characteristics ◽  
Compositional Analysis ◽  
Oil And Gas Industry ◽  
Acid System ◽  
Gas Industry ◽  
Petroleum Production ◽  
Study Results ◽  
Temperature Levels ◽  
Dissolution Efficiency

Abstract Oil and gas industry deals with fluid streams with different ions and concentrations that might cause scale precipitation. The scale precipitation, will thereafter, affect the fluid flow characteristics. Many problems will be raised by the scale deposition that affects the overall petroleum production. This paper aims to develop a non-corrosive acid system with high dissolution efficiency for field complex scales that have sulfates and sulfides minerals. The paper provided a series of lab analysis that covers the compositional analysis for the collected scale sample, and evaluating the developed acid system for compatible and stable properties, dissolution efficiency, and the corrosive impact. A field scale sample that has a composite chemical composition of paraffin, asphaltene, sulfides and sulfates compounds with different weight percentages by employing the diffraction of X-ray technology. Developing the new scale dissolver was achieved by specific compositional study for the organic acids to achieve high dissolution efficiency and low corrosive impact for the field treatment operations. The study results showed the successful scale removal for the developed dissolver at low temperature of 95 and 113 °F for surface treatment jobs. The dissolution efficiency recorded 62 and 71 % for 17 hours at the temperature levels respectively. The fluid showed a stable and compatible performance and has a pH of 12. The corrosion test was conducted without any scale inhibitors and the results showed the low corrosion effect by 0.0028 lbm/ft2. The obtained successful results will help to dissolve such complex field scales, maintain the well equipment, and maintain the petroleum production from scale issues.

Toward Developing Non-Corrosive Acid System for Complex Scales Removal

2021 ◽  
Author(s):  
Hany Gamal ◽  
Salaheldin Elkatatny ◽  
Saad Al-Afnan ◽  
Mohamed Bahgat
Keyword(s):  
Oil And Gas ◽  
Flow Characteristics ◽  
Compositional Analysis ◽  
Oil And Gas Industry ◽  
Acid System ◽  
Gas Industry ◽  
Petroleum Production ◽  
Study Results ◽  
Fluid Flow Characteristics ◽  
Dissolution Efficiency

Abstract Oil and gas industry deals with fluid streams with different ions and concentrations that might cause scale precipitation. The scale precipitation, will thereafter, affect the fluid flow characteristics. Many problems will be raised by the scale deposition that affects the overall petroleum production. This paper aims to develop a non-corrosive acid system with high dissolution efficiency for field complex scales. The paper provided a series of lab analysis that covers the compositional analysis for the collected scale sample, and evaluating the developed acid system for compatible and stable properties, dissolution efficiency, and the corrosive impact. A field scale sample that has a composite chemical composition of calcium carbonate, calcium sulfate, kaolinite, barium sulfate, magnetite, and halite with different weight percentages by employing the diffraction of X-ray technology. Developing the new scale dissolver was achieved by specific compositional study for the organic acids to achieve high dissolution efficiency and low corrosive impact for the field treatment operations. The study results showed the successful scale removal for the developed dissolver at 160 and 210 °F by dissolution efficiency 100 % for 5 hours. The fluid showed a stable and compatible performance with low rate of solids precipitation after the scale treatment (2.3 %). The developed dissolver has a pH of 9. The corrosion test was conducted without any scale inhibitors and the results showed the low corrosion effect by 0.0129 lbm/ft2. The obtained successful results will help to dissolve such complex field scales, maintain the well equipment, and maintain the petroleum production from scale issues.

scholarly journals New Environmentally Friendly Acid System for Iron Sulfide Scale Removal

2019 ◽  
Vol 11 (23) ◽  
pp. 6727 ◽  
Author(s):  
Hany Gamal ◽  
Khaled Abdelgawad ◽  
Salaheldin Elkatatny
Keyword(s):  
Oil And Gas ◽  
Iron Sulfide ◽  
Environmentally Friendly ◽  
Oil And Gas Industry ◽  
Surface Flow ◽  
Acid System ◽  
Field Sample ◽  
Scale Removal ◽  
Well Completion ◽  
Static Conditions

Iron sulfide scale is a common problem in the oil and gas industry. The precipitation of the iron sulfide scale on the well completion tools or inside surface flow lines restricts the flow of the produced fluids and might affect the integrity of the pipelines or the surface and subsurface tools. Failure of the downhole completions tools will not only reduce the production rates but it might require workover and remedial operations that will add extra cost. The main objective of this paper is to evaluate a new environmentally friendly acid system (NEFAS) for iron sulfide scale removal using an actual field sample. The scale sample collected from a natural gas well is dominated by pyrrhotite (55%) in addition to calcite (21%), pyrite (8%), and torilite (6%) with minor traces of hibbingite, siderite, geothite, akaganeite, and mackinawite. High-temperature solubility tests were performed by soaking 2 g of the scale field sample with 20 cm3 of the NEFAS under static condition at 125 °C for different time periods (2, 6, 12, 18, and 24 h). The solubility results were compared with commercial solutions for iron sulfide scale removal such as hydrochloric acid (15 wt.%), glutamic acid diacetic acid (GLDA, 20 wt.%), and high density converters (HDC-3) under the same conditions. The corrosion test was performed at 125 °C for the developed solution after mixing with 2 wt.% corrosion inhibitor (CI) and 2 wt.% corrosion intensifier (CIN). The results were compared with HCl (15 wt.%) under the same conditions. NEFAS consists of 75 wt.% biodegradable acid at pH of 0.04. NEFAS achieved 83 g/L solubility of iron sulfide scale after 6 h at 125 °C under static conditions. The solubility efficiency was very close to 15 wt.% HCl after 24 h where the solubility was 82 and 83 g/L for NEFAS and HCl, respectability. HDC-3 and GLDA (20 wt.%) achieved a lower scale solubility; 18 g/L and 65 g/L respectively, after 24 h. NEFAS achieved a corrosion rate of 0.211 kg/m2 after adding the CI and and CIN compared to 0.808 kg/m2 for HCl. The new environmentally friendly biodegradable acid system provides efficient performance for the scale removal without harming the environment and causing any side effects to the operation.

Comparative analysis of production potential in Bulla-deniz and Umid gas-condensate fields

2020 ◽  
pp. 21-26
Author(s):  
E.H. Ahmadov ◽  
Keyword(s):  
Oil And Gas ◽  
Reduction Rate ◽  
Chemical Properties ◽  
Gas Production ◽  
Layer System ◽  
Reservoir Properties ◽  
Technical Parameters ◽  
Recovery Curves ◽  
Well Model ◽  
Drilling Technology

The paper studies the reduction rate of gas production in the wells of Bulla-deniz field drilled to VIII horizon. With this purpose, geological (reservoir properties, oil-gas saturation, net thickness, formation pressure and temperature, formation heterogeneity, multi-layer system, tectonic faults, physical-chemical properties of oil and gas etc.) and technological (well structure, measuring and transportation system, well operation regime, drilling technology etc.) conditions of formation were analyzed and the well model of VII and VIII horizons of Bulla-deniz field using these geological and technical parameters developed as well. For the estimation of impact of geological and technical aspects on production, sensitivity analysis was carried out on the models. The suggestions for elaboration of uncertainty of geological and technical parameters affecting production dynamics were developed. To reveal the reasons for production differences of the wells, it was proposed to install borehole manometers, to obtain the data on pressure recovery curves, drainage area, skin-effect impact, permeability and to develop a study plan of bottomhole zone with acid.

Pre-Treatment Experimental Study of Organic Acid: An Alternative Means to Overcome Inorganic Scale Build-Up Problem in Deep Well

2021 ◽  
Author(s):  
Bagus Muliadi Nasution ◽  
Andrew Yonathan ◽  
Muthi Abdillah ◽  
Wang Zhen
Keyword(s):  
Hydrochloric Acid ◽  
Formic Acid ◽  
Organic Acid ◽  
Corrosion Inhibitor ◽  
Corrosion Test ◽  
Oil And Gas ◽  
Experimental Studies ◽  
Oil And Gas Industry ◽  
Scale Inhibitor ◽  
Pre Treatment

Abstract Organic acid has been widely applied for inorganic scale treatment in oil and gas industry including well stimulation and scale inhibitor. Thanks to its low corrosivity and slower reaction rate with rock, organic acid is considered to offer better performance comparing to strong acid - Hydrochloric Acid (HCl). Yet, proper treatment requires vigorous analysis and experiment in order to meet foremost expectations. Besides, mistreatment of scale could result in formation damage including clay precipitation. Pre-treatment experiments were performed on Zelda field at South East Sumatera block, that has faced with scale problem for ages. Water sample was taken from flowing Zelda A-08 well to be analyzed for mineral's saturation level. Scale was extracted from three sources including tubing, sand bailer, and Electrical Submersible Pump (ESP) of Zelda A-08. Those scale were treated in X-Ray Powder Diffraction (XRD) for mineral composition, and solubility test that utilized two types of acid system - formic acid (HCOOH) and hydrochloric acid (HCl) for comparison. Anti-swelling test and corrosion test were performed to examine the effectiveness of clay stabilizer and corrosion inhibitor. As for carbonate analysis, both formic acid 9% and HCl 15% have comparable solubility (98.17% vs 98% for tubing's scale, 91.86% vs 82.79% for ESP's scale, and 70.30% vs 68.07% for sand bailer's scale). Yet, longer reaction is carried out by formic acid 9% (1 hour) comparing to HCl 15% (18 minutes). For silicate analysis, HF-formic acid provided the higher solubility than HF-HCl (8.34% vs 5.67% for ESP's scale and 30.48% vs 25.68% for sand bailer's scale). On anti-swelling test, by reducing swelling tendency up to 62.6%, it proves that examined clay stabilizer works perfectly against swelling potential of clay, despite of high swelling tendency of sand bailer's scale (25.8%). On corrosion test, adding on corrosion inhibitor (pyridine-based) into solution results in regular HCl 15% has corrosion rate 26.279 g/m2.h which is much higher (300%) than HF-HCl (7.977 g/m2.h) and HF-formic acid (8.229 g/m2.h). Based on pre-treatment test, formic acid 9% together with examined corrosion inhibitor and clay stabilizer, can be used as an alternative to regular HCl 15% for stimulation purpose where more areas will be covered that previously left unreachable by regular acid 15%. In addition, potentially more effective squeezed scale inhibitor using organic acid can also be achieved by performing further experiments. The method presented in this paper for pre-treatment experimental studies of organic acid can provide engineers with intensive guide to meet the best result of organic acid treatment.

Applied Mechanics Problems in the Oil and Gas Industry

1986 ◽  
Vol 39 (11) ◽  
pp. 1687-1696 ◽  
Author(s):  
Jean-Claude Roegiers
Keyword(s):  
Oil And Gas ◽  
Petroleum Industry ◽  
Oil Industry ◽  
Oil And Gas Industry ◽  
Production Equipment ◽  
Paper Briefly ◽  
Research Activity ◽  
Gas Industry ◽  
Well Production ◽  
Current Research Activity

The petroleum industry offers a broad spectrum of problems that falls within the domain of expertise of mechanical engineers. These problems range from the design of well production equipment to the evaluation of formation responses to production and stimulation. This paper briefly describes various aspects and related difficulties with which the oil industry has to deal, from the time the well is spudded until the field is abandoned. It attempts to delineate the problems, to outline the approaches presently used, and to discuss areas where additional research is needed. Areas of current research activity also are described; whenever appropriate, typical or pertinent case histories are used to illustrate a point.

Experimental and CFD Investigations to Evaluate the Effects of Fluid Viscosity and Particle Size on Erosion Damage in Oil and Gas Production Equipment

2010 ◽  
Author(s):  
Risa Okita ◽  
Yongli Zhang ◽  
Brenton S. McLaury ◽  
Siamack A. Shirazi ◽  
Edmund F. Rybicki
Keyword(s):  
Particle Size ◽  
Oil And Gas ◽  
Production Equipment ◽  
Gas Production ◽  
Inconel 625 ◽  
Sand Particle ◽  
Fluid Viscosity ◽  
Particle Sizes ◽  
Erosion Rates ◽  
Particle Speed

Zhang et al (2006) utilized CFD to examine the validity of erosion models that have been implemented into CFD codes to predict solid particle erosion in air and water for Inconel 625. This work is an extension of Zhang’s work and is presented as a step toward obtaining a better understanding of the effects of fluid viscosity and sand particle size on measured and calculated erosion rates. The erosion rates of Aluminum 6061-T6 were measured for direct impingement conditions of a submerged jet. Fluid viscosities of 1, 10, 25, and 50 cP and sand particle sizes of 20, 150, and 300 μm were tested. The average fluid speed of the jet was maintained at 10 m/s. Erosion data show that erosion rates for the 20 and 150 μm particles are reduced as the viscosity is increased, while surprisingly the erosion rates for the 300 μm particles do not seem to change much for the higher viscosities. For all viscosities considered, larger particles produced higher erosion rates, for the same mass of sand, than smaller particles. Concurrently, an erosion equation has been generated based on erosion testing of the same material in air. The new erosion model has been compared to available models and has been implemented into a commercially available CFD code to predict erosion rates for a variety of flow conditions, flow geometries, and particle sizes. Since particle speed and impact angle greatly influence erosion rates of the material, calculated particle speeds were compared with measurements. Comparisons reveal that, as the particles penetrate the near wall shear layer, particles in the higher viscosity liquids tend to slow down more rapidly than particles in the lower viscosity liquids. In addition, CFD predictions and particle speed measurements are used to explain why the erosion data for larger particles is less sensitive to the increased viscosities.

Experimental Evaluation of a New Nonaromatic Nonionic Surfactant for Deep Carbonate Stimulation

2021 ◽  
pp. 1-12
Author(s):  
Khatere Sokhanvarian ◽  
Cornell Stanciu ◽  
Jorge M. Fernandez ◽  
Ahmed Farid Ibrahim ◽  
Harish Kumar ◽  
...  
Keyword(s):  
Nonionic Surfactant ◽  
Pore Volume ◽  
Inductively Coupled Plasma ◽  
Oil And Gas ◽  
Low Cost ◽  
Acid System ◽  
Matrix Acidizing ◽  
High Corrosion ◽  
First Choice ◽  
The Stability

Summary Matrix acidizing improves productivity in oil and gas wells. Hydrochloric acid (HCl), because of its many advantages such as its effectiveness, availability, and low cost, has been a typical first-choice fluid for acidizing operations. However, HCl in high-pressure/high-temperature (HP/HT) wells can be problematic because of its high reactivity, resulting in face dissolution, high corrosion rates, and high corrosion inhibition costs. Several alternatives to HCl have been tested; among them, emulsified acid is a favorable choice because of its inherent low corrosion rate, deeper penetration into the reservoir, fewer asphaltene/sludge problems, and better acid distribution due to its higher viscosity. The success of the new system is dependent upon the stability of the emulsion, especially at high temperatures. The emulsified acid must be stable until it is properly placed, and it must also be compatible with other additives in an acidizing package. This study develops a stable, emulsified acid system at 300°F using aliphatic nonionic surfactants. This paper introduces a new nonaromatic, nonionic surfactant to form an emulsified acid for HP/HT wells. The type and quality of the emulsified acid were assessed through conductivity measurements and drop tests. The thermal stability of the system was monitored as a function of time through the use of pressure tubes and a preheated oil bath at 300°F. A LUMisizer® (LUM GmbH, Berlin, Germany) and Turbiscan® (Formulaction, S. A., L’Union, France) were used to determine the stability and the average droplet size of the emulsion, respectively. The viscosity of the emulsified acid was measured at different temperatures up to 300°F as a function of shear rate (1 to 1,000 s−1). The microscopy study was used to examine the shape and the distribution of acid droplets in diesel. Coreflood studies at low and high flow rates were conducted to determine the performance of the newly developed stable emulsified acid in creating wormholes in carbonate rocks. Inductively coupled plasma and computed tomography (CT) scans were used to determine the dissolved cations and wormhole propagation, respectively. Superior stimulation results with a low pore volume of acid to breakthrough (PVBT) were achieved at 300°F with the newly developed emulsified acid system. The wormhole propagation was narrow and dominant compared to branched wormholes resulting from conventional emulsified acid systems. Results indicate that a nonionic surfactant with optimal chemistry, such as a suitable hydrophobe chain length and structure, can form a stable emulsified acid. In this study we introduce a new and effective aliphatic nonionic surfactant to create a stable emulsified acid system for matrix acidizing at HP/HT conditions, leading to a deeper penetration of acid with low pore volume to breakthrough. The successful core flood studies in the laboratory using carbonate cores suggest that the new emulsified acid system may efficiently stimulate HP/HT carbonate reservoirs.

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

2020 ◽  
Vol 12 (6) ◽  
pp. 2455
Author(s):  
Hany Gamal ◽  
Salaheldin Elkatatny ◽  
Dhafer Al Shehri ◽  
Mohamed Bahgat
Keyword(s):  
Low Temperature ◽  
Corrosion Rate ◽  
High Performance ◽  
Oil And Gas ◽  
Ethylenediaminetetraacetic Acid ◽  
Gas Production ◽  
Operating Conditions ◽  
Superior Performance ◽  
X Ray ◽  
Dissolution Efficiency

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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