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.

A New Technical Standard Procedure to Measure Stimulation and Gravel-pack Fluid Leak-off under Dynamic Conditions

2015 ◽  
Author(s):  
Mahmoud Asadi ◽  
Brain Ainley ◽  
David Archacki ◽  
Eric Aubry ◽  
Harold Brannon ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Standard Procedure ◽  
Oil And Gas Industry ◽  
Testing Procedure ◽  
Technical Standard ◽  
Gas Wells ◽  
Dynamic Conditions ◽  
Oil And Gas Wells ◽  
Static Conditions ◽  
Gravel Pack

Abstract Historically, leak-off analyses of stimulation fluids have been performed using in-house laboratory procedures. The lack of industry standard procedures to perform leak-off and wall building coefficient analyses of stimulation fluids has introduced inconsistency in both results and reporting for many years. A technical standard adopted in 2006 by both API and ISO for static conditions has provided the oil and gas industry with the first standardized procedure to measure and report leak-off1. However, the more complex testing under dynamic conditions was not addressed. As a result, a group of industry experts have compiled their years of experiences in developing a new technical standard to measure the leak-off characteristics of stimulation and gravel-pack fluids under dynamic flow conditions. Stimulation and gravel-pack fluids are defined, for the purpose of this technical standard, as fluids used to enhance production from oil and gas wells by fracturing and fluids used to place filtration media to control formation sand production from oil and gas wells. Leak-off is the amount of fluid lost to porous media during these operations. The leak-off procedure was developed through the colaberation of several industry companies by evaluating numerous in-house laboratory techniques and conducting round robin testing to ensure that any modifications to these procedures were reliable and repeatable. The new standard provides a step-by-step procedure that includes fluid preparation, experimental equipment design, testing procedure and data analyses for fluids exhibiting viscosity controlled leak-off or wall building characteristics. Example calculations are reviewed within this paper.

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.

Laboratory-Scale Investigation of the Utilisation of Multiple Flat-Fan Nozzles in Descaling Petroleum Production Tubing

2021 ◽  
Author(s):  
Kabir Hasan Yar'Adua ◽  
Idoko Job John ◽  
Abubakar Jibril Abbas ◽  
Salihu M. Suleiman ◽  
Abdullahi A. Ahmadu ◽  
...  
Keyword(s):  
High Pressure ◽  
Oil And Gas ◽  
Gas Production ◽  
Oil And Gas Production ◽  
Scale Removal ◽  
Petroleum Production ◽  
Well Completion ◽  
Water Jets ◽  
Well Integrity ◽  
Injection Pressures

Abstract Despite the recent wide embrace of mechanical descaling approaches for cleaning scales in petroleum production tubings and similar conduits with the use of high-pressure (HP) water jets, the process is still associated with downhole backpressure and well integrity challenges. While the introduction of sterling beads to replace sand particles in the water recorded high successes in maintaining well completion integrity after scale removal in some recent applications of this technique, it is, unfortunately, still not without questions of environmental degradation. Furthermore, the single nozzle, solids-free, aerated jetting descaling technique – recently published widely – is categorized with low scale surface area of contact, low descaling efficiency and subsequent high descaling rig time. The modifications to mechanical descaling techniques proposed in this work involve the use of three high-pressure flat fan nozzles of varying nozzles arrangements, standoff distances and injection pressures to remove soft scale deposits in oil and gas production tubings and similar circular conduits. This experiment provides further insights into the removal of paraffin scales of various shapes at different descaling conditions of injection pressures, stand-off distances and nozzle arrangements with the use of freshwater. The results obtained from this study also show consistency with findings from earlier works on the same subject.

A New Approach To Estimating Ultimate Recovery for Multistage Hydraulically Fractured Horizontal Wells by Utilizing Completion Parameters Using Machine Learning

2021 ◽  
pp. 1-16
Author(s):  
Sulaiman A. Alarifi ◽  
Jennifer Miskimins
Keyword(s):  
Oil And Gas ◽  
Horizontal Wells ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
New Approach ◽  
History Data ◽  
Well Completion ◽  
Production History ◽  
Early Production ◽  
Fractured Horizontal Wells

Summary Reserves estimation is an essential part of developing any reservoir. Predicting the long-term production performance and estimated ultimate recovery (EUR) in unconventional wells has always been a challenge. Developing a reliable and accurate production forecast in the oil and gas industry is mandatory because it plays a crucial part in decision-making. Several methods are used to estimate EUR in the oil and gas industry, and each has its advantages and limitations. Decline curve analysis (DCA) is a traditional reserves estimation technique that is widely used to estimate EUR in conventional reservoirs. However, when it comes to unconventional reservoirs, traditional methods are frequently unreliable for predicting production trends for low-permeability plays. In recent years, many approaches have been developed to accommodate the high complexity of unconventional plays and establish reliable estimates of reserves. This paper provides a methodology to predict EUR for multistage hydraulically fractured horizontal wells that outperforms many current methods, incorporates completion data, and overcomes some of the limitations of using DCA or other traditional methods to forecast production. This new approach is introduced to predict EUR for multistage hydraulically fractured horizontal wells and is presented as a workflow consisting of production history matching and forecasting using DCA combined with artificial neural network (ANN) predictive models. The developed workflow combines production history data, forecasting using DCA models and completion data to enhance EUR predictions. The predictive models use ANN techniques to predict EUR given short early production history data (3 months to 2 years). The new approach was developed and tested using actual production and completion data from 989 multistage hydraulically fractured horizontal wells from four different formations. Sixteen models were developed (four models for each formation) varying in terms of input parameters, structure, and the production history data period it requires. The developed models showed high accuracy (correlation coefficients of 0.85 to 0.99) in predicting EUR given only 3 months to 2 years of production data. The developed models use production forecasts from different DCA models along with well completion data to improve EUR predictions. Using completion parameters in predicting EUR along with the typical DCA is a major addition provided by this study. The end product of this work is a comprehensive workflow to predict EUR that can be implemented in different formations by using well completion data along with early production history data.

scholarly journals Completion Fluid dengan Nitrat - Formate Base

2020 ◽  
Vol 1 (2) ◽  
pp. 41-46
Author(s):  
Mohammad Mahlil Nasution
Keyword(s):  
Oil And Gas ◽  
High Pressures ◽  
Solid Material ◽  
Oil And Gas Industry ◽  
Basic Material ◽  
Formation Damage ◽  
Gas Industry ◽  
Well Completion ◽  
Soluble Solid ◽  
The Impact

Completion Fluid is a Liquid of Salt Solution (Brine), used during the Well Completion, also to Killing Well job, when doing Work Over Wells and Well Services Jobs and Fishing Job  and also functions as Packer Fluid. Completion Fluid is generally used in Reservoir formations that are sensitive to Shales, Clay or other minerals. The purpose of using Completion Fluid is to avoid or reduce formation demage. The formation damage causes reservoir formation that has hydrocarbon potential, after being drilled and produced the flow of oil becomes small and even difficult to flow. Formation damage  need to be given very serious attention so that the Oil production in our country can increase significantly because the impact is that production does not increase significantly, Cost of production is high. If an effort to minimize damage is done optimally, it is expected that production will increase significantly so that the production target from year to year can be achieved. This invention relates to the method of making Completion Fluid for Drilling, Work Over and Well Services as Drilling activities in the Oil and Gas industry, using fresh water and solids as the material, more specifically is a solid which is a soluble solid as a base formula for making the fluid. In this case, the basic material of the solid material used for completion fluid is Nitrate and Alkali Formate. This completion fluid can reach SG (Specific Gravity) up to 2.0. This completion fluid has very low corrosivity (Corrosivity), which is stable at very high temperatures and high pressures.

Application of DFT in Iron Sulfide Scale Removal from Oil and Gas Wells

2019 ◽  
Author(s):  
A. Onawole ◽  
I. Hussein ◽  
M. Saad ◽  
M. Ahmed ◽  
S. Aparicio
Keyword(s):  
Oil And Gas ◽  
Iron Sulfide ◽  
Gas Wells ◽  
Scale Removal ◽  
Oil And Gas Wells

Hybrid Data Driven Approach for Reservoir Production Forecast

2021 ◽  
Author(s):  
Achraf Ourir ◽  
Jed Oukmal ◽  
Baptiste Rondeleux ◽  
Zinyat Agharzayeva ◽  
Philippe Barrault
Keyword(s):  
Data Science ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Machine Learning Algorithms ◽  
Analytical Models ◽  
Reservoir Engineering ◽  
Full Data ◽  
Production Forecast ◽  
Data Set ◽  
Well Completion

Abstract Analytical models, in particular Decline Curve Analysis (DCA) are widely used in the oil and gas industry. However, they are often solely based on production data from the declining wells and do not leverage the other data available in the field e.g. petrophysics at well, completion length, distance to contacts... This paper describes a workflow to quickly build hybrid models for reservoir production forecast based on a mix of classic reservoir methods and machine learning algorithms. This workflow is composed of three main steps applied on a well by well basis. First, we build an object called forecaster which contains the subject matter knowledge. This forecaster can represent parametric functions trained on the well itself or more complex models that learn from a larger data set (production and petrophysics data, synthesis properties). Secondly this forecaster is tested on a subset of production history to qualify it. Finally, the full data set is used to forecast the production profile. It has been applied to all fluids (oil, water, gas, liquid) and revealed particularly useful for fields with large number of wells and long history, as an alternative to classical simulations when grid models are too complex or difficult to history match. Two use cases from conventional and unconventional fields will be presented in which this workflow helped quickly generate robust forecast for existing wells (declining or non-declining) and new wells. This workflow brings the technology, structure and measurability of Data Science to Reservoir Engineering. It enables the application of the state of the art data science methods to solve concrete reservoir engineering problems. In addition, forecast results can be confronted to historical data using what we call "Blind Testing" which allows a quantification of the forecast uncertainty and avoid biases. Finally, the automated workflow has been used to generate a range of possible realizations and allows the quantification the uncertainty associated with the models.

scholarly journals Molecular Design of Novel Chemicals for Iron Sulfide Scale Removal

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Abdulmujeeb T. Onawole ◽  
Ibnelwaleed A. Hussein ◽  
Hassan I. Nimir ◽  
Musa E. M. Ahmed ◽  
Mohammed A. Saad
Keyword(s):  
Density Functional ◽  
Oil And Gas ◽  
Iron Sulfide ◽  
Molecular Design ◽  
Oil And Gas Industry ◽  
Functional Theory ◽  
Gas Industry ◽  
Chelating Ability ◽  
Intramolecular Hydrogen ◽  
The Cost

Scale deposition is a pertinent challenge in the oil and gas industry. Scales formed from iron sulfide are one of the troublous scales, particularly pyrite. Moreover, the use of biodegradable environmentally friendly chemicals reduces the cost compared to the conventional removal process. In this work, the chelating abilities of four novel chemicals, designed using the in silico technique of density functional theory (DFT), are studied as potential iron sulfide scale removers. Only one of the chemicals containing a hydroxamate functional group had a good chelating ability with Fe2+. The chelating strength and ecotoxicological properties of this chemical were compared to diethylenetriaminepentaacetic acid (DTPA), an already established iron sulfide scale remover. The new promising chemical surpassed DTPA in being a safer chemical and having a greater binding affinity to Fe2+ upon optimization, hence, a better choice. The presence of oxime (-NHOH) and carbonyl (C=O) moieties in the new chemical showed that the bidentate form of chelation is favored. Moreover, the presence of an intramolecular hydrogen bond enhanced its chelating ability.

Direct electric heating: an environmentally friendly flow-assurance tool

2013 ◽  
Vol 53 (2) ◽  
pp. 448
Author(s):  
Ingebjørg Lien
Keyword(s):  
Oil And Gas ◽  
Environmentally Friendly ◽  
Electric Heating ◽  
Oil And Gas Industry ◽  
Electrical Circuit ◽  
Flow Assurance ◽  
Critical Temperatures ◽  
Gas Industry ◽  
Field Development ◽  
Hydrate Plug

In subsea flowlines, water in the line can form an ice-like structure called a hydrate plug. Wax appearance in flowlines also is a common flow assurance issue. Hydrate and wax appearance can reduce or stop production for weeks. Preventing hydrate and wax in pipelines is a major concern for the oil and gas industry. Direct electric heating (DEH) is a modern and environmentally friendly flow-assurance tool that can reduce capital expenditures (CAPEX) and operating expenditures (OPEX) in field development, reduce the probability of pollution, and reduce handling of toxic disposals as a result of traditional chemical flow assurance methods. DEH is based on using the pipeline as part of the electrical circuit, generating losses in the steel pipe to keep the pipeline and its content above the critical temperatures. Use of DEHs also increases the efficiency at the process plant after planned or unplanned production stops. For marginal fields and fields with heavy or waxy oil, DEH is a flow-assurance method that can enable these fields to be developed profitably. DEH is now a mature technology used for 13–14 years on the Norwegian continental shelf and technology implemented and used in West Africa recently. How successful this technology has been can be summarised by the Tyrihans field where Statoil quoted that they—on this project alone—saved about $USD175 million by implementing DEH. Wärtsilä has been part of the DEH development in Norway since the 90s, and undertakes design and supply of the complete topside power package in addition to electric and optical protection specially developed for DEH systems.

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.

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