Spe Production & Operations最新文献

{"title":"Dimer Indolizine Derivatives of Quaternary Salt Corrosion Inhibitors: Enlightened High-Effective Choice for Corrosion Prevention of Steel in Acidizing","authors":"Zhen Yang, Yefei Wang, M. Finšgar, Fengtao Zhan, Huayou Hu, Jiajia Wu, Wengang Ding, M. Ding, Wuhua Chen","doi":"10.2118/200098-pa","DOIUrl":"https://doi.org/10.2118/200098-pa","url":null,"abstract":"\u0000 For decades, increasingly severe downhole conditions call for superior and less-expensive corrosion inhibitors (CIs) for acidizing in petroleum production. Inhibitors that exhibit satisfactory protective ability at relatively low concentration are of great interest to most scholars in this area. In this work, two newly obtained dimer indolizine derivatives that were derived from the conventional quaternary quinolinium salts were introduced as potential highly efficient acidizing CIs. The indolizine derivatives could perform well alone, even without any synergistic component, in concentrated hydrochloric acid (HCl).\u0000 Two quinoline ammonium salts, ethyl acetate quinolinium chloride (EAQC) and n-butyl quinolinium chloride (BuQC), were synthesized in advance by means of the quaternarization process. Afterward, in the presence of alkali, the ammonium salts could then get converted into the corresponding novel dimer indolizine derivatives easily by means of a 1,3-dipolar cycloaddition reaction in a relatively high yield. The derivatives were purified and their accurate chemical structures were confirmed by elementary analysis, nuclear magnetic resonance (NMR), and mass spectrometry (MS). Dimer derivatives of two quinoline salts were prepared successfully and characterized separately as C26H23N2O4Cl and C26H27N2Cl. Corrosion-inhibition performance of the quaternary quinoline salts as well as the related dimer indolizine derivatives in concentrated HCl for N80 steel was investigated by gravimetric research, electrochemical method, and scanning electron microscopy (SEM) energy dispersive X-ray analysis. The thermodynamic aspect of the inhibition was also discussed.\u0000 The structure of EAQC and BuQC are very close to the quinolinium salt inhibitors that are commonly used as key components in commercially accessible acid CI products. However, under alkaline condition, EAQC and BuQC would easily be transformed to dimer indolizine derivatives that possess a general “indolizine” structure. That is the reason why the targeted molecules are recognized as “dimer indolizine derivatives.” Both the derivatives have good thermal stability at approximately 248°F and are easily soluble in acid solution. The surprising difference in the anticorrosion effect between the original quinoline salts and their dimer derivatives was proved by weight-loss experiments in 15 wt% HCl at 194 and 248°F with dosage ranges from 0.01 to 0.5 wt%. The derivatives could retard the corrosion of steel considerably at a much lower concentration compared with their precursors. A 0.1-wt% dosage of indolizine derivatives could increase the inhibition efficiency (IE) of N80 steel remarkably, to approximately 99.0% in 15 wt% HCl at 194°F. Results obtained from gravimetric tests and electrochemical methods are in good agreement and confirmed the well-behaved inhibition of the derivatives.\u0000 We predict that the inhibition will be enhanced apparently when similar quinoline or pyridine ammonium salt ar","PeriodicalId":22071,"journal":{"name":"Spe Production & Operations","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2118/200098-pa","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42315169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of Slug/Churn Transition for Viscous Upward Two-Phase Flows in Vertical Pipes","authors":"G. Abdul-Majeed, Mahshid Firouzi","doi":"10.2118/203832-PA","DOIUrl":"https://doi.org/10.2118/203832-PA","url":null,"abstract":"\u0000 In this study, we investigate the effect of liquid viscosity (μL) on the slug/churn transition in gas/liquid flows in vertical pipes. A total of 80 experimental churn-flow data points from two different sources are compiled as a data set, covering liquid viscosities from 17.23 to 586 mPa·s. Air was used in these studies as a gas phase with two different liquids, aqueous glycerol and a commercial synthetic mineral oil, flowing in vertical pipes of 0.0192- and 0.0508-m inner diameter (ID). The data set is used to examine the existing slug/churn-flow-transition models and provide further insights into the effect of μL on the transition. The existing models are categorized into two groups according to their response of the slug/churn transition to the increase in liquid superficial velocity (Vsl) on the Vsg/Vsl flow map. The first category exhibits a decrease in superficial gas velocity (Vsg) with the increase in Vsl at slug/churn (the transition concave to the left). The other one predicts an increase in Vsg with increasing of Vsl (the transition concave to the right). Analysis of the data set reveals that on the Vsg/Vsl flow map, the slug/churn transition moves toward lower superficial gas velocities as liquid viscosity increases and occurs approximately at a constant Vsg for low to medium Vsl. The predictions of these models were tested against the data set and poor results were shown by most models. The best performance is given by the Abdul-Majeed (1997) model. A dimensional analysis is applied in the present study to develop a new slug/churn-transition model. This analysis indicates that the transition is related to three dimensionless numbers, namely gas- and liquid-phase Froude numbers, in addition to the inverse liquid-viscosity number. An improved revision to the Abdul-Majeed model is achieved using these three dimensionless numbers. The revision enables the model to predict the transition for low, medium, and high liquid viscosity. The revised model clearly outperforms all the existing models for the present data and viscous data from independent studies. Furthermore, the revised model exhibits the expected trend against changes in pipe diameter and gas density.","PeriodicalId":22071,"journal":{"name":"Spe Production & Operations","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2118/203832-PA","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46823553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compatibility Test and Nanoparticles Stability: Comparison between Smart Soft Water and Smart Hard Water","authors":"S. Ezzati, E. Khamehchi","doi":"10.2118/204218-pa","DOIUrl":"https://doi.org/10.2118/204218-pa","url":null,"abstract":"Smart water is one of the most common methods for increasing oil recovery factor (RF) widely used in both sandstone and carbonate reservoirs. Smart water changes oil reservoir rock wettability from oil-wet to water-wet and increases oil RF. When smart water is combined with formation water, it can form sediments that will be called incompatibility, the results of which will be precipitation of inorganic scale deposition in surface facilities, flow lines, well tubing, gravel packs, and in the reservoirs. In contrast, by stabilizing the various nanoparticles in water, beneficial changes such as wettability alteration, sand production prevention, and decreased fines migration can be realized in oil reservoirs. Therefore, water compounds should be designed to have a minimum amount of incompatibility and the greatest amount of nanostability.For this study, the formation water and seawater were created in the laboratory. Seawater was diluted in different concentrations and combined with formation water, and the best-diluted seawater was selected. Sensitivity analysis was performed using the Taguchi algorithm on diluted water, and it was used to make smart soft water (SSW) and smart hard water (SHW). In this project, we aimed to compare the amount of incompatibility and nanostability in SSW and SHW. To analyze the amount of incompatibility, different compositions of SSW and SHW were made and combined with formation water. In all cases, soft water was more compatible with formation water. To compare stability, different nanofluids were made in optimized soft water and hard water. By testing the zeta potential, it was observed that soft water shows more stability. In general, this study proved two advantages of SSW over SHW.","PeriodicalId":22071,"journal":{"name":"Spe Production & Operations","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2118/204218-pa","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43046402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of Gel Plug for Temporary Blocking and Well-Killing Technology in Low-Pressure, Leakage-Prone Gas Well","authors":"Xiong Ying, Xu Yuan, Zhang Yadong, F. Ziyi","doi":"10.2118/204213-pa","DOIUrl":"https://doi.org/10.2118/204213-pa","url":null,"abstract":"\u0000 A gel-plug system for temporary blocking technology is proposed in this paper to address the prevalent leakage of killing fluid in low-pressure wells; the low technical strength of existing gel plugs for temporary blocking in well killing; difficult-to-control crosslinking time; and gel embrittlement and the difficulty of breaking certain gel plugs. A mixture of etherified galactomannan plant gum, isooctanol polyoxyethylene ether surfactant, and oil phase was used as a thickener. An inorganic salt complex containing long-chain polyhydroxy alcohol was used as a crosslinker and the concentration of long-chain polyhydroxy alcohol far exceeds the theoretical amount required to complex the metal ion. A mixture of polyhydroxy alcohol with a small amount of weak acid was used as a crosslinking regulator. Finally, a mixture of sodium thiosulfate and long-chain quaternary ammonium salt surfactant was used as a stabilizer. Laboratory evaluations showed that this gel-plug system can be directly pumped into the wellbore after being mixed homogeneously, and the viscosity of the system on the surface can be controlled by the amount of crosslinking regulator. The viscosity of the gel-plug system after gelling was high (viscoelastic solid colloid); the initial viscosity reached 30 000 mPa·s at 120°C and retained a semisolid gel shape after aging for 72 hours. Right-angle thickening occurred when the gel warmed to target-zone temperature. The acidic liquid breaker acted quickly, and the viscosity of the broken fluid was lower than 5 mPa·s after 1 to 4  hours. This gel plug for temporary blocking and well-killing technology was successfully applied in a low-pressure, leakage-prone gas well. No gas, pressure, or liquid remained in the open well after killing, the wellhead was successfully replaced, and the tubing was successfully removed. The gel plug also exhibited self-healing: The hole formed by the tubing could be filled and sealed automatically by the gel plug in the annulus. The static friction (outer wall) of 73-mm tubing in the gel plug was 39.6 t/km; the dynamic friction (outer wall) after tubing removal was 7.2 t/km. This gel plug thus shows promise as a temporary blocking technology in workover operations of low-pressure, leakage-prone gas wells.","PeriodicalId":22071,"journal":{"name":"Spe Production & Operations","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2118/204213-pa","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44246923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Health, Safety, and Environment Operational Excellence through Full Utilization of Intelligent Field","authors":"K. Yateem, H. Muailu, Mohammed Gomaa, O. Ayoola","doi":"10.2118/203837-pa","DOIUrl":"https://doi.org/10.2118/203837-pa","url":null,"abstract":"\u0000 Working in the oil industry comes with unique challenges and risks, and so extra precautions and safety measures coupled with strict environmental compliance must be applied. Contrary to the common belief that strict safety enforcement could hinder smooth operations, the deployment of new technologies and enhanced solutions of processes has enabled operational excellence (OE) and improved safety performance. In this paper, we demonstrate health, safety, and environment performance improvement through implementing two main initiatives:\u0000 The first category has initiatives that require less intervention or personnel; for example, the deployment of cableless pressure sensors or permanent monitoring systems in key wells to ensure continuous real-time pressure data to monitor reservoir pressure. The second category has initiatives that mitigate traditional health, safety, and environment risks; for example, through use of multiphase flow meters (MPFMs) to collect accurate and continuous flow measurements instead of traditional well testing.\u0000 Optimizing operations costs while maintaining a high-level of safety is achieved through a dedicated team working in a state-of-the-art Production Operations Surveillance Hub (POSH), which enables the monitoring of wells in real time, making production optimization decisions, and ensuring a high level of well integrity via close monitoring of wells and assets.","PeriodicalId":22071,"journal":{"name":"Spe Production & Operations","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2118/203837-pa","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41627267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct Injection of Biomineralizing Agents to Restore Injectivity and Wellbore Integrity","authors":"Catherine M. Kirkland, R. Hiebert, R. Hyatt, J. Mccloskey, J. Kirksey, Abby Thane, A. Cunningham, R. Gerlach, L. Spangler, Adrienne J Phillips","doi":"10.2118/203845-pa","DOIUrl":"https://doi.org/10.2118/203845-pa","url":null,"abstract":"\u0000 In this manuscript, we describe the second of two field demonstrations of microbially induced calcium carbonate precipitation (MICP) performed in a failed waterflood injection well in Indiana. In 2012, fracture-related flow pathways developed in the wellbore cement, causing injection water to bypass the oil-bearing formation and enter a high-permeability sandstone thief zone, thereby substantially decreasing injection pressure. In the first field demonstration, our study team characterized the well's mode of failure and successfully applied MICP to decrease flow through the defective cement. However, because the MICP treatment was conducted using a bailer delivery system, the degree of permeability reduction achievable was not adequate to fully restore the historic injection pressure of 1,400 psi at 1 gal/min. For the second field demonstration (reported herein), a direct injection system was developed that substantially increased the injection volume of MICP-promoting fluids. Two strategies were implemented to produce more ureolytic microbes: resuspending concentrated frozen cells immediately before injection and scaling up the bioreactor growth capacity. Multiple pulses of microbes and urea-calcium media were pumped into a string of 1-in.-diameter tubing separated by brine spacers and injected continuously at a flow rate of 3.4 to 1.4 gal/min. During the third day of injection, an injection pressure of 1,384 psi at a flow rate of 1.4 gal/min was achieved, and the experiment was terminated. This study demonstrates that MICP can be successfully used in large-volume applications where the time frame for the delivery of reactants is limited. This finding has significant relevance for commercialization of the MICP biotechnology in the oil and gas industry.","PeriodicalId":22071,"journal":{"name":"Spe Production & Operations","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2118/203845-pa","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48395606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Enhanced-Oil-Recovery Chemicals on Oil/Water-Separation Processes, from Laboratory Scale to Flow-Loop Scale","authors":"C. Cassar, A. Mouret, M. Salaün, M. Klopffer","doi":"10.2118/200455-pa","DOIUrl":"https://doi.org/10.2118/200455-pa","url":null,"abstract":"With the use of chemically based enhanced-recovery methods, water management, which has always been a major point in the production-operation processes, needs to be considered and adapted because the whole water cycle will be affected by the backproduced additives. Enhanced-oil-recovery (EOR) chemicals such as alkali molecules, high-molecular-weight polymers, or surfactant formulation will dramatically modify pH, viscosity, and phase behaviors of produced fluids. The main issues encountered in oil/water-separation processes are directly related to the risk of tight emulsion formation, which might considerably complicate the surface-water-treatment processes.\u0000 The objective of this paper is to underline the effect of one of these chemicals, a surfactant formulation, on the produced-water cycle when they are backproduced first at a laboratory scale and second on a large-scale separation unit using an industrial-size flow loop and a well-instrumented separator.\u0000 Our goal is first to investigate the impact of surfactant on the water/oil mixture separation efficiency, and second, to find an efficient demulsifier specific for this case. At the laboratory scale, the impact of surfactant within produced fluids on oil/water separation (regarding separation kinetics but also oil/water phase qualities) will be evaluated by performing bottle tests.\u0000 Those laboratory bottle tests enabled us to screen different parameters, such as the surfactant concentration, the water cut that can strongly affect the type of formed emulsion [oil in water (O/W) or water in oil (W/O)], and its stability. The oil/water phase qualities were quantified and correlations with parameters related to the large-scale experiment were drawn, helping us in defining the key parameters for this campaign.\u0000 Indeed, to get closer to a field case, a semi-industrial-scale test platform was used. The flow loop reproduces separation process conditions encountered in a field treatment facility, including the production separator, the controlled temperature, and the oilfield chemical injection rate. The main operating conditions are liquid flow rates and temperature. The influence of different parameters can be studied, such as the surfactant concentration, mixing conditions, residence time, water cut, and the presence of chemicals that will help the separation process. Different types of emulsions were formed depending on the conditions, and their stability was evaluated through the measurement of separation profiles using a single electrode capacitance probe (SECAP) within the separator.\u0000 The results obtained show how the surfactant, as well as the demulsifier concentration, have led to different types of emulsions and have affected the oil/water separation processes. These tests have confirmed that separation is more difficult in the presence of surfactant and that water quality was degraded. It has also been shown that separation processes can be greatly improved by adding some EOR-compliant dem","PeriodicalId":22071,"journal":{"name":"Spe Production & Operations","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2020-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2118/200455-pa","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42808086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Productivity Improvement by Reperforation of Multistage-Fractured Wells in High-Pressure/High-Temperature Tight Gas Reservoirs: A Case History","authors":"Ryosuke Kidogawa, N. Yoshida, K. Fuse, Yuta Morimoto, K. Takatsu, Keisuke Yamamura","doi":"10.2118/197590-pa","DOIUrl":"https://doi.org/10.2118/197590-pa","url":null,"abstract":"\u0000 Productivity of multistage-fractured gas wells is possibly degraded by conductivity impairments and non-Darcy flow during long-term production. Such degradations are pronounced by flow convergence to short perforated intervals, while it is challenging to identify degraded stages for remediation. Moreover, remedial actions can be expensive under a high-pressure/high-temperature (HP/HT) environment. A field case demonstrates successful application of reperforation as a cost-effective way to mitigate the flow convergence by prioritizing targets with multirate production-logging (PL) results.\u0000 This work presents theoretical investigations using numerical simulations and field execution of reperforation for a well with six-stage fracturing treatments in a HP/HT volcanic gas reservoir onshore Japan. Apparent conductivity reduction was suspected during more than 15 years of production, and it was pronounced by non-Darcy flow effects associated with flow convergence to short perforated intervals. Multirate PL was used to identify impaired stages by quantifying the inflow-performance relationship (IPR) of each stage under transient flow-after-flow (FAF) testing. The impaired stages were reperforated, adding perforation intervals with wireline-conveyed perforators. Pressure-buildup (PBU) tests before and after the job and post-job PL were used to validate productivity improvements.\u0000 Target zones for reperforations were identified and prioritized with results of the multirate PL conducted. The stage IPRs were drawn, and relatively large non-Darcy effects were identified in three stages by shapes of the IPRs and/or decreasing inflow contributions as the surface rate increased. Also, a temperature log showed steep temperature change at the bottom of the fourth stage; the fracture might propagate below the perforated interval. Ranges of production increment were estimated using a numerical model calibrated against the estimated stage IPRs. The estimated increment was in the range of 15 to 30% with the planned reperforation program, while its magnitude depended on the connection between new perforations and existing fractures. Afterward, the reperforation job was performed and the gas rate was confirmed to be increased by 26% with the same wellhead pressure after 1 month of production. The post-job PL was conducted 3 months after the reperforation. The well IPR was improved, implying reduction of the non-Darcy effects. Results of PBU tests also indicated reduction of skin factor. The stage IPRs were redrawn with the post-job PL, and they suggested clear improvements in two stages where screenout occurred during fracturing treatments and a stage where significant non-Darcy effect was suspected.\u0000 The workflow and strategy in this paper can be applied for productivity restoration in a cost-effective way to multistage-fractured gas wells with short perforated intervals and impaired apparent conductivity during long-term production. Especially, the interpreted res","PeriodicalId":22071,"journal":{"name":"Spe Production & Operations","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2118/197590-pa","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48934531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Benchmarking of Pulsed Field Gradient Nuclear Magnetic Resonance as a Demulsifier Selection Tool with Arabian Light Crude Oils","authors":"D. S. Marques, R. White, Sajjad Al-Khabaz, Mustafa Al-Talaq, Jabr Al-Buainain","doi":"10.2118/203820-pa","DOIUrl":"https://doi.org/10.2118/203820-pa","url":null,"abstract":"\u0000 The use of chemical demulsifiers in the treatment of crude oil emulsions is an essential step in processing facilities worldwide. Each production facility requires specific demulsifier reformulations as the crude characteristics change. The assessment of candidate demulsifiers before online field trials is currently done with bottle tests. Such tests are manual, based on water dropout visually measured by operators. The development of a method that can automatically determine the speed and amount of water dropout without the laborious need to manually record water separation would significantly decrease human error. Pulsed field gradient nuclear magnetic resonance (PFG-NMR) is used as a classification tool to qualitatively rank the efficiency of different demulsifiers in breaking Arabian Light emulsions. This imaging method can evaluate demulsifier action based on the emulsion characteristics; for example, rate of sedimentation and coalescence and formation of a dense packed zone (rag layer). The results are validated against field trials performed in gas-oil separation plants (GOSPs) at two Saudi Arabian facilities. There was good agreement between the PFG-NMR method and field trials. The results were found to correspond to the water dropout in the first stage of crude oil treatment in processing plants (production traps).","PeriodicalId":22071,"journal":{"name":"Spe Production & Operations","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2118/203820-pa","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41566282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Investigation of Polymer-Induced Fouling of Heater Tubes in the First-Ever Polymer Flood Pilot on Alaska North Slope","authors":"Anshul Dhaliwal, Yin Zhang, A. Dandekar, S. Ning, J. Barnes, R. Edwards, W. Schulpen, D. Cercone, J. Ciferno","doi":"10.2118/200463-ms","DOIUrl":"https://doi.org/10.2118/200463-ms","url":null,"abstract":"\u0000 Polymer flooding is being pilot tested for the first time in the Schrader Bluff viscous oil reservoir at the Milne Point Field on Alaska North Slope (ANS). One of the major concerns of the operator is the impact of polymer on the oil production system after polymer breakthrough, especially the polymer-induced fouling issues in the heat exchanger. This study investigates the propensity of polymer fouling on the heater tubes as a function of different variables, with the ultimate goal of determining safe and efficient operating conditions. A unique experimental setup was designed and developed in-house to simulate the fouling process on the heating tube. The influence of heating tube skin temperature, tube material, and polymer concentration on fouling tendency was investigated. Each test was run five times with the same tube, and in each run, the freshly prepared synthetic brine and polymer solution was heated from 77°F to 122°F to mimic field-operating conditions. The heating time and fouling amount were recorded for each run. Cloud point measurement has also been conducted to find the critical temperature at which the polymer in solution becomes unstable and precipitates out. The morphology and composition of the deposit samples were analyzed by environmental scanning electron microscopy (ESEM) and X-ray diffraction (XRD), respectively. It was found that the presence of polymer in produced fluids would aggravate the fouling issues on both carbon steel and stainless steel surfaces at all tested skin temperatures. Only higher skin temperatures of 250°F and 350°F could cause polymer-induced fouling issues on the copper tube surface, and the fouling tendency increased with polymer concentration. At the lower skin temperatures of 165°F, no polymer-induced fouling was identified on the copper tube. A critical temperature that is related to the cloud point of the polymer solution was believed to exist, below which polymer-induced fouling would not occur and only mineral scale was deposited but above which the polymer would aggravate the fouling issue. The cloud point of the tested polymer solution was determined to be between 220°F and 230°F. From a practical safer design standpoint, we recommend a value of 220°F for operational purposes on the pilot site. The heating efficiency of the tube would be decreased gradually as more fouling material accumulates on its surface. If polymer precipitated and deposited on the surface, it would bond to the mineral crystals to form a robust three-dimensional network structure, resulting in a rigid polymer-induced fouling. The study results have provided practical guidance to the field operator for the ongoing polymer flooding pilot test on ANS.","PeriodicalId":22071,"journal":{"name":"Spe Production & Operations","volume":null,"pages":null},"PeriodicalIF":1.2,"publicationDate":"2020-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.2118/200463-ms","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67778632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}