Wax Appearance Research Articles

Mechanism study on rheological response of thermally pretreated waxy crude oil

Pre-heating treatment significantly influences the low-temperature flow characteristics of waxy crude oil, yet its underlying mechanism warrants further investigation. This study explores the effects of pre-heating temperatures (60–110 °C) on the rheological characteristics of waxy crude oil from Nanyang using 1H NMR, DSC, Microscopic Observation, and Rheological Property Test. Findings reveal that asphaltenes increasingly dissolve at the pre-heating temperature of 70 °C, improving their capacity to act as nucleation sites for wax crystals. Consequently, the wax appearance temperature (WAT) increases. Meanwhile, the rheological parameters of the crude oil decrease and wax crystals exhibit smaller and tighter rod-like structures. Further growing the pre-heating temperature to 80 °C induces a comprehensive effect: alterations in asphaltene polarity, hindrance of asphaltene aggregation by alkyl side chains, and self-aggregation of alkyl side chains. This results in decreased WAT, along with the lowest rheological parameter values, with wax crystals appearing as the smallest and tightest dot-like shapes. At 80 °C, the optimal ratio between asphaltene polarity and alkyl side chain characteristics promotes strong nucleation and co-crystallization between asphaltene and wax crystals, maximizing asphaltene's ability to enhance the crude oil's low-temperature flowability. However, as the pre-heating temperature continues to rise, WAT decreases slightly and the rheological response starts to deteriorate.

New intelligent models for predicting wax appearance temperature using experimental data – Flow assurance implications

Wax deposition is a major problem during petroleum production causing flow rate reduction and blockage of tubing, pipelines, and surface facilities. Wax deposition occurs when crude oil temperature falls below wax appearance temperature (WAT). WAT is an important parameter for wax deposition modeling and developing, testing, and selecting appropriate wax inhibitors. WAT can be determined in laboratory using several different techniques. Although, each method has its own disadvantages including being time-consuming, expensive, inaccurate, or posing health and safety risks. Experimental WAT data are very scarce in the literature. Reliable and accurate correlations and models for WAT prediction are rare, as well. Hence, development of fast, easy, and reliable models for prediction of WAT is inevitable. The main objective of this research work was to develop and introduce novel intelligent models for precise production of WAT. The artificial intelligent (AI) algorithms used include least-squares support-vector machines (LSSVM), recurrent neural network (RNN), and Adaptive neuro-fuzzy inference system (ANFIS). A high-quality dataset was assembled using experimental WAT data collected from the literature. The dataset consists of 81 experimental which is the largest dataset ever reported. The gathered dataset covers a wide range of density from 0.71 to 0.89 g/cm3, wax content from 0.61 to 25.78 wt%, and Pour point from −36 to 37°C. The selected input parameters include oil density, wax content, and pour point determined using a rigorous feature selection analysis. Statistical analysis showed that pour point has the highest impact on WAT prediction. The modeling results showed that the LSSVM model is the superior model with coefficient of determination (R2) of 0.9893, a root mean squared error (RMSE) of 0.1655, and an average absolute relative deviation (AARD) of 9%. The LSSVM model outperformed the only existing smart model in terms of both performance and accuracy. The proposed smart model can be used for prediction of WAT which is an essential parameter in all wax related research.

Wax "Tails" Enable Planthopper Nymphs to Self-Right Midair and Land on Their Feet.

The striking appearance of wax 'tails'-posterior wax projections on planthopper nymphs-has captivated entomologists and naturalists alike. Despite their intriguing presence, the functional roles of these formations remain largely unexplored. This study leverages high-speed imaging to uncover the biomechanical implications of wax structures in the aerial dynamics of planthopper nymphs (Ricania sp.). We quantitatively demonstrate that removing wax tails significantly increases body rotations during jumps. Specifically, nymphs without wax undergo continuous rotations, averaging 4.2 ± 1.8 per jump, in contrast to wax-intact nymphs, who do not complete a full rotation, averaging only 0.7 ± 0.2 per jump. This along with significant reductions in angular and translational velocity from takeoff to landing suggest that aerodynamic drag forces on wax structures effectively counteract rotation. These stark differences in body rotation correlate with landing success: Nymphs with wax intact achieve a near perfect landing rate of 98.5%, while those without wax manage only a 35.5% success rate. Jump trajectory analysis reveals that wax-intact jumps transition from parabolic to asymmetric shapes at higher takeoff velocities and show a significantly greater reduction in velocity from takeoff to landing compared to wax-removed jumps, demonstrating how wax structures help nymphs achieve more stable and controlled descents. Our findings confirm the aerodynamic self-righting functionality of wax tails in stabilizing planthopper nymph landings, advancing our understanding of the complex relationship between wax morphology and aerial maneuverability, with broader implications for wingless insect aerial adaptations and bioinspired robotics.

Novel Optical Methodology Unveils the Impact of a Polymeric Pour-Point Depressant on the Phase Morphology of Waxy Crude Oils.

Crude oil, also known as petroleum, plays a crucial role in global economies, politics, and technological advancements due to its widespread applications in industrial organic chemistry. Despite environmental concerns, the dwindling supply of easily accessible oil reservoirs necessitates the exploration of unconventional resources, such as heavy and extra-heavy oils. These oils, characterized by high viscosity and complex composition, pose challenges in extraction, transportation, and refinement. With decreasing temperatures, heavy oils undergo phase changes, with transitions from Newtonian to non-Newtonian fluid behavior, leading to difficulties in transportation. Alternative methods, such as the use of polymeric pour-point depressants, help mitigate flowability issues by preventing wax precipitation. Understanding the properties of waxy crude oil, such as the wax appearance temperature (WAT), is crucial for effective mitigation strategies. The objective of this research is to determine the WATs of different types of waxy crude oils through a comparative analysis using advanced techniques such as cross-polar microscopy (CPM), standard rheology, and differential scanning calorimetry (DSC). Disparities in WAT identified through different analytical methods highlight the potential of microscopy to enhance our understanding of complex fluid dynamics in real time in order to proactively identify and address crystallization issues in oilfields.

Synthesis and application of polyer additive system for reducing the pour point depressant of crude oil in exploitation, transportation

Problems encountered when exploiting and transporting crude oil containing solid paraffins is that it easily crystallizes under normal temperature, causing many challenges such as paraffin wax deposition, reduced flow rate, gel formation, loss of pipe pressure... When the crude oil temperature is below the wax appearance temperature (WAT), paraffin will precipitate and separate from the oil. Many solutions that have been and are being used such as insulation, mechanical, thermal, chemical methods, using wax inhibitors - pour point depressants (PPD) and dispersants... The method of using additives to increase solidification temperature or inhibit wax, improve the rheology of crude oil and reduce paraffin deposition is considered one of the most effective method. In this study, polymers made from a combination of three monomers, behenyl acrylate, stearyl methacrylate and vinyl acetate, were studied to find the most optimal combination for the purpose of manufacturing pour point lowering additives for oils.

Development of predictive model for determination of paraffin deposition in Kazakh crude oil

Kazakhstan's crude oil contains significant amounts of heavy hydrocarbons that solidify as wax at lower temperatures, leading to reduced flow rates and potential blockages in pipelines. Paraffin, a substantial component of crude oil, crystallizes below its pour point, posing challenges for maintaining efficient crude oil transportation. Addressing wax deposition is essential for optimizing oil flow and meeting global energy demand. This article presents an innovative method for forecasting paraffin deposition in Kazakh crude oil, using its chemical composition and thermobaric conditions. The methodology encompassed data analysis, ASTM-standard laboratory tests, and computations employing modified equations for fusion properties calculation. Outcomes comprise computed temperatures, enthalpy, and heat capacity related to melting, along with revised correlations for melting and pour points specific to Kazakh crude oils. The melting point correlation was modified to fit the properties of Kazakh crude oils, resulting in standard deviation of 0.55 %. Computed pour points for hydrocarbons improved by 17 % respectively. As a result of the research a novel software tool was developed and evaluated, highlighting the project’s contribution in providing an adjusted thermodynamic model for paraffin deposition forecasting. Comparisons between the developed software, PVTSim, and field data showed the wax appearance temperature (WAT) predictions closely aligned, with 0.74 % of error. This numerical tool shows potential in predicting wax deposition, thus aiding in the planning of oil production and refining processes in Kazakhstan. The importance of this work extends to its potential economic impact on companies and the nation, as well as its environmental benefits by facilitating eco-friendly planning of oil production facilities. Future research could expand on these findings to further enhance predictive models of paraffin precipitation across diverse conditions

Review on Mitigation of Paraffin Wax Formation using Jatropha-Based Inhibitor

Wax deposition in pipelines and wells is one of the problems in the oil and gas industry. Wax deposition can lead to pipeline blockages, reduced flow capacity, and even production facility or pipeline closures. Various methods and techniques have been developed to mitigate wax deposition, including chemical, mechanical, and thermal methods. Inhibition of wax deposition using chemical methods involves using chemical additives to prevent or reduce wax buildup on pipelines or wellbores. Chemical methods for mitigating wax deposition can include using plant-based inhibitors as effective additives. Biosurfactants, which are surfactants derived from plant-based sources, can be used in chemical methods to address wax deposition issues effectively. Jatropha seeds are rich sources of natural chemicals that can be used to effectively control wax because of the wide variety of natural chemical compounds they contain. This paper aims to provide an overview of the potential of jatropha oil as a wax inhibitor.Keywords: crude oil, flow assurance, plant-based inhibitor, temperature, wax deposition, wax appearance, wax inhibitors

The Effect of Heat Tracing Installation for Wax Prevention on Onshore Buried Swampy Pipelines

Transporting crude oil using pipelines is a widely adopted method globally. In one segment owned by PT. XYZ, especially in swampy areas, the fluid temperature tends to drop below the wax appearance temperature (WAT) during oil transportation. This is due to the relatively low temperature in swamp areas caused by heat loss to the environment. The solubility of paraffin in crude oil drastically decreases as fluid temperature drops, causing wax molecules to precipitate and deposit on the cold pipe walls. PT. XYZ employs chemical treatment by adding a pour point depressant (PPD) to lower the pour point temperature (PPT). However, PPD is effective only at certain temperatures, necessitating a study for alternative treatments. Another method involves installing heaters on the pipeline to reduce the viscosity of transported crude oil and enhance its flowability, either through direct heating or heat tracing using insulation with low thermal conductivity. Therefore, in PT. XYZ's case, an analysis is required to identify locations where fluid temperature decreases occur to ensure precise heater installation. Various software tools, including OLGA, have been developed to predict and describe wax deposition phenomena and temperature decreases along the pipeline. OLGA software can simulate locations of fluid temperature decreases in the pipeline, estimate heat loss along the pipeline, and simulate heat tracing technologies to prevent wax deposition. Simulation results indicate that wax deposition can be prevented by installing skin effect heat tracing with a heating power of 15 W/m and insulated with 2-inch aerogel, maintaining the oil temperature downstream at 157.34°F, well above the desired 115°F threshold.

Melorheostosis (Leri's Disease): A Review.

Melorheostosis is a noncancerous bone disease characterized by abnormal bone and soft tissue growth. Despite being identified almost a century ago, there are still many unknown aspects surrounding this condition. It can often be an incidental discovery, with patients experiencing associated pain and deformities. Diagnosis typically relies on X-rays, although not all cases exhibit the classic candle wax appearance. A new imaging sign known as the "dumpling on a plate sign" has been proposed for flat bones for both MRI and CT scans. A biopsy may be necessary in cases of uncertainty, as there is not a definitive histological feature. It is not uncommon for melorheostosis to be linked with other conditions, and a collaborative approach involving a multidisciplinary team should be considered. This condition should be considered in the differential diagnosis of sclerotic bone conditions. Management is generally aimed at symptom relief, either through conservative measures or surgical intervention.

Thermal removal mechanism of paraffin deposits: Impact of flowrate on removal efficiency

Active heating is increasingly explored as a cost-effective strategy for managing wax deposition in production flowlines. While these methods are commonplace throughout the industry to maintain or raise the temperature of the production fluid above the wax appearance temperature (WAT), there are no clear guidelines for wax removal using active heating. In this study, a novel dynamic microscopic visualization technique is used to observe the effects of the flow regime on the removal process. At high enough temperatures, 50.6 °C and 43.3 °C, 100% removal is observed in both turbulent and laminar cases. A removal temperature of 37.0 °C resulted in 72.5% removal under turbulent conditions, and 97% removal under laminar conditions. No reduction in thickness was observed in either case when removing at a temperature of 30.6 °C. Turbulent conditions were also shown to significantly increase the heating time required before detachment compared to laminar conditions at the same removal temperature. The turbulent experiments required 2.7 times as long for detachment to occur when removal temperatures were raised to 43.3 °C, and 4.6 times as long when temperatures were raised to 37.0 °C. Turbulent conditions are also shown to require higher temperatures to trigger the removal process, likely due to the harder deposits formed at higher flow rates. This analysis sheds light on the impact flow regime and deposit properties have on the removal process. The results obtained in this study enhance the understanding of the impact of flow on thermal removal and this knowledge is necessary for accurate removal modeling.

Pickering stabilization of water-in-crude oil emulsions by paraffin wax crystals: Insights from X-ray scattering

Previous studies suggest asphaltenes are active materials at the oil-water interface, affecting the formation and stability of crude oil emulsions. However, even oils of low asphaltene content generate stable emulsions, indicating the involvement of other oil fractions. Due to the role of paraffin waxes as Pickering stabilizers or gel network formers in emulsions from other applications, this study explores their stabilization capacity in water-in-oil (W/O) emulsions and their interaction with other fractions with interfacial activity. The extraction and physicochemical characterization of paraffin waxes from two Brazilian crude oils allowed us to correlate their properties with the emulsification of both crude and model oils. Removal of asphaltenes enhances emulsion stability. Emulsion preparation with crude oils without waxes and asphaltenes demonstrates the participation of other amphiphilic components in emulsion formation, whereas waxes are necessary for their stabilization. Experiments with emulsions formed by a model oil confirmed the combined action of waxes and an amphiphilic material in the formation and stabilization of the interfacial film. However, the combination of waxes and asphaltenes are ineffective. Small-angle X-ray scattering (SAXS) analysis revealed that waxes only form a lamellar structure when highly purified, suggesting Pickering stabilization rather than the formation of a gel network. In conclusion, polar oil fractions other than asphaltene play a crucial role in emulsion formation, whereas paraffin wax provides Pickering stabilization, even beyond the wax appearance temperature (WAT). This study enhances our understanding of the mechanisms governing waxy Brazilian crude oil emulsions.

Rheological behavior of high-pour-point oil: Insights into viscosity–temperature prediction and viscoelastic-yielding transition

The rheological characteristics of high-pour-point (high-PPT) oil are crucial for its economical and safe production and transportation. However, current research on the viscosity–temperature prediction and viscoelastic-yielding transition of high-PPT oil is insufficient. The Arrhenius formula faces challenges in accurately depicting the viscosity–temperature relationship, and there is a lack of a quantitative description of the viscoelastic-yielding transition behavior in gelled high-PPT oil. This study addresses these gaps through a series of rheological experiments. The results reveal that the viscosity–temperature relationship of high-PPT oil can be classified into three regions, each associated with a sequentially increasing activation energy Ea. Introducing two characteristic parameters, T0 and n, yields a modified Arrhenius formula with an extended range of applicability. Thixotropy and gelation process experiments demonstrate an exponential increase in thixotropic strength with a decreasing temperature below the wax appearance temperature, while an optimum cooling rate maximizes the gelation degree of high-PPT oil. A brittleness index BI was defined to quantitatively describe the fracture mode of gelled crude. Critical characteristic strains and BI exhibit a decrease with an increase in the reciprocal of the average free degree 1/wfree, where the diminishing trend of BI follows a robust power-law form. This comprehensive investigation contributes valuable insights into the rheological behavior of high-PPT oil, offering a foundation for more accurate modeling and control strategies in its production and transportation.

Features of Wax Appearance Temperature Determination of Waxy Crude Oil Using Attenuated Total Reflection Fourier Transform Infrared Spectroscopy Under Ambient and High Pressure.

The wax appearance temperature (WAT), being one of the key characteristics of waxy crude oil and other waxy substances, is used for the necessary assessment of the phase stability of materials during various technological processes. However, the determination of this parameter as well as peculiarities of wax formation under high gas pressure suffers from the lack of suitable techniques for this task. To address this issue, an attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR) method has been applied for the first time to measure the WAT of waxy crude oil under high gas pressure. Carbon dioxide (CO2), nitrogen, and natural gas were used in the study due to their widespread applicability as injection gases in enhanced oil recovery methods. The S2/S1 versus temperature method based on changes in the band of rocking vibrations of the CH2 group was applied to determine WAT. It was found that the ATR FT-IR method based on the proposed dependence S2/S1 versus temperature gives lower WAT values compared to those observed by viscometry, magnetic resonance imaging inspection, and cross-polarized microscopy methods for the waxy crude oil studied. A detailed analysis was carried out using variable-temperature ATR FT-IR spectra of waxy crude oil in the temperature region near the WAT. Essentially different dynamics of wax crystal formation in waxy oil sample and model paraffin solution were demonstrated during the cooling process. The results obtained by high-pressure ATR FT-IR showed that CO2 and natural gas reduce the WAT, while nitrogen has virtually no effect. In addition, for the studied oil, it was found that high pressure of CO2 and natural gases leads to a visual decrease in the amount of wax crystals precipitated, but not to the complete disappearance of microcrystals at a certain temperature and pressure. The results obtained proved that ATR FT-IR can be an effective method for proper determinations of WAT under high-pressure conditions similar to those met in practice.

Wax appearance temperature in crude oils measured by surface plasmon resonance

To predict and quantify the wax appearance temperature in crude oils, we proposed and implemented a well-explored sensing method known as surface plasmon resonance. This phenomenon occurs when an incident light beam couples into a metallic surface. As sensing method, this phenomenon has been widely used in biosensing applications. In this research, we showed the effectiveness of the surface plasmon resonance sensing technique in hydrocarbon sensing in general and in crude oil wax appearance prediction in particular. To the authors knowledge, this is the first exploration of monitoring wax deposition events from crude oil using surface plasmon resonance measurements. A compact optical sensor was developed from an ultra-thin layer of gold deposited on a sapphire prism and supported by a new data analyzing metric to analyze the acquired reflected beam intensity profile and detect the precipitation of crude oil wax or other hydrocarbon particles under varying-temperature and low-pressure conditions. The obtained wax appearance temperatures using the introduced on-site method were found to be comparable with the literature measurements using the common in-lab Cross-Polarization Microscopy method.

Enhancement of flow characteristics in waxy crude oil under the influence of subtle magnetic fields

The study aims to improve flow in weakly magnetized transportation of waxy crude oil. The magnetization of waxy crude oil with a weak magnetic field strength below 100 mT was investigated using magnetization processing equipment. By employing the orthogonal experimental principle and data processing method, the magnetization effect of crude oil and its primary influencing factors were examined and analyzed. A new concept, equivalent viscosity reduction rate, is introduced along with criteria for evaluating the effectiveness of reducing magnetization viscosity. The equivalent viscosity reduction rate increases as magnetization intensity rises, but initially increases and then decreases as magnetization temperature increases. The viscosity reduction is most significant when the magnetization temperature is close to the wax appearance temperature, resulting in an 18% equivalent viscosity reduction rate. We clarify the mechanism of enhancing crude oil flow with magnetic fields by integrating previous microscopic studies. The viscosity reduction effect of magnetized wax crystals is orderly under a weak magnetic field. The nucleation of magnetic wax limits the viscosity reduction effect of magnetization at high temperature. The reduction in the length-diameter ratio of magnetized wax crystals and boundary box dimensions contributes to enhancing the low temperature fluidity of crude oil.

Polymer nanocomposites to modify crude oil waxy crystallization: Influence of content and type of clay (mineral)

Some operational problems in the oil industry are due to the precipitation of paraffins. To prevent them, a possible strategy is the use of polymeric additives. Polymeric nanocomposites have proved to be a promising alternative in waxy model systems. The article reports the evaluation of nanocomposites of poly(ethylene-co-vinyl acetate) (10 mol% vinyl acetate) (EVA) with palygorskite, montmorillonite or halloysite as pour point reducers in different types of crude oil: two paraffinic oils (°API = 26.4 and 28.8) and one oil without n-alkanes, which was doped with different wax concentrations (pour point of 56–58 °C). The performance of nanocomposites was evaluated by pour point (PP), microcalorimeter (μDSC), optical microscope and rheological measurements. The nanocomposites reduced PP of different oils, being more efficient than pure EVA since the nanocomposites reduced PP by up to 43.5 °C, whereas the EVA reduced PP by a maximum of 9 °C. In general, the additives modified the precipitated wax crystals, but they had difficulty acting in the oil with the highest n-alkane content. Nanocomposites reduced the wax appearance temperature of the oil with 24% w/w n-alkanes by approximately 12 °C. They also reduced the viscosity of the oil samples. Among the evaluated materials, EVA:palygorskite and EVA:halloysite nanocomposites were the most efficient pour point reducers.

Thermodynamic Modeling Approach Assists Mitigation of Wax Deposition

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 211943, “Prediction and Prevention of Wax Deposition in MERO-006T: A Thermodynamic Modeling Approach,” by Obiora Nwosu, Olugbenga Daodu, SPE, and Basil Ogbunude, SPE, Shell, et al. The paper has not been peer reviewed. _ Well MERO-006T is an oil development well that came into production in March 1988 and has been plagued with incessant wax buildup. Research indicates that a wax-inhibition tool can be deployed in the well. The complete paper highlights the thermodynamic modeling approach adopted to determine the wax appearance temperature (WAT) in Well MERO-006T, the well-modeling approach to estimate the depth at which wax formation would occur, and the optimal depth for the wax-inhibition tool based on life-cycle-production expectations from the well. Introduction Problems associated with wax deposition can occur anywhere in the production system, from the reservoir to the terminal. Wax deposits result from the cooling effect of oil flowing from high-pressure reservoirs through the wellbore to the surface. Depressurization of the oil as it is produced leads to its expansion and temperature drop, which induces crystallization of wax. Considering the effects of wax deposition on producing wells and facilities, prevention of the phenomenon is preferable to correction. Challenges Well MERO-006T was drilled and completed as a single-string single in November 1981 on the Q2100X sand. The crude oil in the reservoir is waxy and has resulted in several wax-cutting jobs across the production life of the well. By February 1989, the production rate had declined to 198 BOPD on 28/64-in. bean. A dewaxing job was completed, and production rose steadily, peaking at 1012 BOPD at 195-psig tubinghead pressure and 0% basic sediment and water in May 1991, after which the well quit production because of wax by November of that year. Several unsuccessful attempts were made to produce the well until March 1994, when stimulation, wax cutting, and nitrogen-lifting intervention was performed. In April 1994, the interval produced dry at an average rate of 160 BOPD on 36/64-in. bean until January 1995, when it quit again. Wax cutting was performed in June 1997; the interval produced dry at an average rate of 300 BOPD on 36/64-in. bean. The well produced at approximately 300 BOPD until March 2003, when production rate dropped to 170 BOPD. Solvent soak and dewaxing was performed in Q4 2004, and the well was opened to flow; production fluctuated between 500 and 100 BOPD. The well was closed in for low productivity as the result of wax formation in October 2005. However, in 2017, the well’s B annulus pressure was found to be higher than maximum allowable annulus surface pressure at the wellhead. Post-risk assessment, the well was classified as high-risk. In 2018, a remediation using conformance control was performed, but this was unsuccessful. It was decided to carry out a workover to restore well integrity. The cumulative production from this interval has been recorded as 1.485 million STB.

Technology Focus: Flow Assurance (November 2023)

This year has seen a focus on gas development projects and the energy transition. Flow assurance plays an interesting role in this area. Even though the attention has been on the energy transition, where gas development is concerned, the production processes through which gas is produced cannot be ignored. Thus, flow-assurance issues remain prevalent today, and an analysis of existing solutions, key to the success of oil and gas producing facilities, needs to be addressed. Tackling mixed-scale issues in the oil field using a novel robust scale dissolver (RSD) was studied in paper SPE 211187. Scaling, an incompatible-fluids-related flow-assurance problem in oil and gas wells at various locations in the Malaysian basin, results in rapid oil production decline. RSD is said to be capable of dissolving up to 100% of mixed scales in 24 hours at well temperatures with no incompatibility with production chemicals, pumping, and wireline components. This was done under laboratory conditions. A field trial was completed, with outstanding results for the RSD as it proved capable of reviving the well by resolving mixed-scale issues. Paper SPE 211943 discusses a thermodynamic modeling approach for prediction and prevention of wax deposition. Wax deposition, an oilfield problem prevalent with aging wells, requires a degree of accuracy with prediction to have better control over prevention approaches. The paper discusses the thermodynamic modeling approach used to determine the wax appearance temperature in a well. This tool also confirmed the optimal depth at which to place a wax-inhibition tool based on the life-cycle expectations of the well. This improved well availability by 30%. Paper OTC 32170 addresses performance mapping of a multiphase-flow model. Exploration-data-analysis techniques were used that enabled a comprehensive analysis of several independent data sets from various origins. The analyses provided actionable and more-general insights that would have been otherwise obscured were individual data sets to be analyzed independently. These papers addressed prevailing issues critical for success and production optimization. Addressing the dissolution of mixed scale is a pressing need in modern operations without necessarily finding the scales in isolated conditions. Wax remediation relies highly on accurate temperature data for maximum efficiency and cost savings. I highly recommend reading the second highlighted paper to understand how the well availability of 30% was achieved. Data analytics in oil and gas enables actionable insights easily identified by the last reviewed paper. I trust, with these updates in flow assurance in recent times, we are well placed and assured of production-facility support for the coming years, contributing positively to the goals of the energy transition through fuels such as gas. Recommended additional reading at OnePetro: www.onepetro.org. SPE 213817 Multifunctional Flow Assurance Inhibitors: Three Birds With One Stone? by Malcolm A. Kelland, University of Stavanger, et al. SPE 215003 Significant Reduction of the Viscosity of Waxy Oils by Electrical Treatment by Hao Wang, The University of Texas at Austin, et al.

Effects of surface roughness on wax deposition

Interior surfaces of crude oil pipelines are far from smooth when they enter service and tend to become rougher through their operational life. Despite this, it is common for models of wax deposition to assume the surface is smooth, or else to ignore roughness altogether. To evaluate the validity of this assumption, in this work, we experimentally explored the importance of roughness on wax deposition. We applied different surface finishes to create several cold fingers with different surface roughnesses, and then collected mass, thickness, and composition data from the deposits that formed on each cold finger at several sets of rotational rates and bulk oil temperatures. It was found that surface roughness has a significant effect on deposit mass, with smoother surfaces generating fewer deposits than rougher surfaces. The effect of roughness was largely independent of rotation rate, but showed a strong dependence on bulk temperature. In particular, the difference in deposit mass due to roughness became much larger when the bulk temperatures were higher than the wax appearance temperature (WAT). These observations suggest that surface roughness plays a significant role in the wax deposition process and should not be ignored in models aiming for high-accuracy predictions. Additionally, the complex interactions between temperature and roughness suggest that a combined mechanism of gelation and preferential crystallization may better explain incipient deposition.

Development of Predictive Model for Wax Formation in Deep-water Pipeline Using Machine learning

Wax deposition in deep sea pipelines can affect oil and gas production. It happens when the pipeline temperature drops below the wax appearance temperature, causing the wax to solidify and stick to the pipeline walls. This paper discusses the limitations of current models in predicting wax deposition in pipelines and proposes the development of more complex, intelligent models that are accurate, resilient, and adaptable to novel input-output scenarios. It also highlights various methods for preventing wax deposition, including the use of chemical inhibitors and thermal remediation techniques. The paper aims to develop a neural network modeling approach for predicting wax deposition potential in producing reservoirs to prevent accumulation before removal. The parameters that were used are wax molecule concentration gradient at pipe wall, temperature gradient at pipe wall, reported wax deposition rate, the pipe wall shear stress, and crude oil viscosity. The radial basis function neural network (RBFNN), is based on the machine learning technique. RBFNN is a good choice for building a predictive wax deposition rate model because it is highly accurate, robust to noise and outliers, computationally efficient, can model complex nonlinear relationships, suitable for real-time applications and requires less training data. The RBF neural network is constructed using MATLAB. The outcomes and experimental data are consistent with a 1.5 percent relative inaccuracy when compared to prior studies. The R^2 value was 0.9906, R value was 0.9953 and the RMSE value was 0.8598. The RBF neural network-based approach for predicting wax deposition rate was successful.