Oil Production Systems Research Articles

Vertical distribution of biofilm communities along an injection wellbore in a deep petroleum reservoir

In petroleum production, microbial research has been widely carried out to serve different engineering applications. For instance, studies on microbial-induced corrosion (MIC) control and microbial-enhanced oil recovery (MEOR) focus on the microbial activities in surface pipelines and in subsurface strata (oil reservoirs), respectively. However, the living microorganisms attaching to the inner surfaces of vertical wells as biofilms has not attracted much attention In a normal water-flooded oil-production system, the water is transferred between the surface and subsurface reservoirs through the vertical wells so that the wellbore biofilms are able to constantly affect the surface and subsurface communities. Therefore, it is necessary to reveal the structure and function of the sessile community along the vertical wellbore. Since in situ sampling from underground vertical wells is technologically complex and expensive, in this study, biofilm samples were obtained during well workover from well tube segments corresponding to different original depths (approximately 0 m, 300 m, 800 m, and 1300 m). Moreover, the injection water was also sampled. The results of 16S rRNA gene library sequencing showed that the microbial community in the water phase was distinct from that found in the biofilms (dissimilarity 0.63–0.78), although they shared 200–272 OTUs. At the phylum level, the dominant phylum, Euryarchaeota , accounted for 21.5%–35.8% in the four biofilms, while only 11.7% in the water phase. Proteobacteria was the dominant phylum in the water phase (74.6%), while accounted for only 7.7%–20.1% in the biofilms. With increasing depth from 0 m to 1300 m, the richness and diversity of biofilms declined (Chao index of 608.8 to 442.4, Shannon index of 4.01 to 3.48), and the bacterial abundance of biofilms declined from 78.4% to 63.5%, while the archaeal abundance increased from 21.6% to 36.5%. The geothermal gradient, depleted oxygen and even turbulence were the significant factors affecting the depth-dependent variation in the communities. For instance, the relative abundance of the hydrogenotrophic genera increased from 8.62% to 28.8% with increasing depth. In addition, the sudden variation of wellbore biofilms suggested a presumed boundary of the microbial ecosystem around the depth of 1000 m, which is consistent with existing reports. This is the first study to directly investigate and reveal the depth-dependent distribution of the wellbore community along a deep well (depth >1300 m). The distinct and depth-dependent communities suggested that direct investigation is necessary for completely understanding and efficiently controlling microbial activities in oil production processes, including MIC control and MEOR. • Biofilms at different depths from an injection well were sampled during workover. • There are abundant microorganisms living in wellbore environments as biofilms. • Biofilm communities show a depth-dependent distribution along the deep well. • Those biofilms interact with the entire oil production system by fluid circulation. • Understanding wellbore biofilm is essential for corrosion control and oil recovery.

Technology Focus: EOR Operations (November 2021)

As the discovery rate of new hydrocarbon resources decreases, the need for more-efficient enhanced-oil-recovery (EOR) processes increases. Unlike in the past, however, when the efficiency was defined in terms of maximizing the recovery factor (RF), the new interpretation of efficiency is based on optimizing the balance between RF and the reduction of carbon footprint. This is done through an integrated approach in which both surface and subsurface elements of the oil-production systems are used to determine energy efficiency and carbon footprint of a unit volume of oil produced by EOR methods. When choosing traditional EOR methods, new innovations may be needed to arrive at new injectant composition to reduce emissions or make the process more efficient. Adding chemicals to the injectant gas to improve the mobility ratio and increase the sweep efficiency is desirable. One example is the use of hydrogels. These are hydrophilic structures that swell when hydrated. Hydrogels are of interest in EOR because of their ability to respond to stimuli such as pH, temperature, light, and ionic strength. EOR methods that involve use of fresh water are also switching to alternative methods that reduce or remove its usage as part of water sustainability. The produced water could be treated properly to make it suitable for injection. Alternatively, polymers that are effective under high salinity or temperature could be used to deal with injecting saline water. For unconventional reservoirs, waterless fracturing techniques are progressing. Paper SPE 201609 discusses the application of a reversible hydrogel that can be added to the injected carbon dioxide (CO2) stream in order to make it a more-efficient injectant for EOR and, hence, create more opportunity for CO2 storage. Paper SPE 202809 deals with utility of new polymers that are suitable for injection into carbonate reservoirs under high-temperature and ultrahigh-salinity conditions. Finally, paper OTC 30437 discusses ways of mitigating safety risks associated with CO2 waterless fracturing in unconventional reservoirs as part of water sustainability as well as prevention of environmental pollution. Recommended additional reading at OnePetro: www.onepetro.org. SPE 200357 - Fundamental Investigation of Auto-Emulsification of Water in Crude Oil: An Interfacial Phenomenon and Its Pertinence for Low-Salinity EOR by Duboué Jennifer, TotalEnergies, et al. SPE 205118 - Experimental Design and Evaluation of Surfactant Polymer for a Heavy-Oil Field in South of Sultanate of Oman by Ali Reham Al-Jabri, Petroleum Development of Oman, et al. SPE 200256 - Chemical Enhanced Oil Recovery and the Dilemma of More and Cleaner Energy by Rouhi Farajzadeh, Delft University of Technology, et al.

Implementing genetic algorithms for optimizing integrated oil production systems

Implementing genetic algorithms for optimizing integrated oil production systems

Postharvest Fruit Detachment in Oil Palm Bunches with Ethephon and Ethylene Gas Application

The processing of oil palm fresh fruit bunches (FFB), together with loose fruits, in the current mill operation contributes to oil loss and high free fatty acids (FFA), affecting crude palm oil quality. Fruit detachment induced by ethephon and ethylene may mitigate the current processing issues. This study shows that a 0.50% (v/v) ethephon application by the evaporation method induced the highest fruit detachment of 30.8 ± 1.1% after 24 h at room temperature, with the FFA content in the extracted crude palm oil at 0.34 ± 0.09%. Ethephon application was effective on bunches between 14 and 28 kg, and fruit detachment was higher in ripe and underripe bunches at 24.1 ± 0.9% and 23.2 ± 0.1%, respectively. A significant fruit detachment of 47.2 ± 2.4% was achieved when the bunches were also stripped mechanically, but the FFA content increased almost 4-fold, from 1.0 ± 0.2% to 3.8 ± 1.2%. The application of ethylene gas at 750 ppm yielded 29.4 ± 1.9% fruit detachment. The findings present the possibility of using ethylene as an indirect method for minimizing oil loss without increasing the FFA content in future crude palm oil production systems.

Compressor Piping Design Effect on Vibration Data

One of the systems for oil and gas production supports is the nitrogen compression system. Problem found that condition of the compressor has high vibration with the maximum overall the first compressor is 9,813 mm / s RMS, the second compressor is 7,439 mm / s RMS, the third compressor is 7,430 mm / s RMS, the fourth compressor is 13.47 mm / s RMS, the fifth compressor is 13,220 mm / s RMS, and sixth compressor already damaged. This research will discuss the nitrogen compression process in terms of the characteristics of the output fluid flow from the compressor using computational fluid dynamics. The first piping system shows that the standby compressor's flow has a higher pressure reaching 10.72 - 11.82 Pa but it is still acceptable. The second piping system with two compressors in operation shows that the pipeline flows in the opposite direction with high pressure. Flow turbulence occurs, resulting in a higher speed. The highest pressure in the pipeline reaches 44.79 Pa, mostly at the fifth and sixth compressors. The conclusion from this research there is high pressure backflow when one compressor stops and another compressor start running. Prevents direct pressure to the compressor or the condensed fluid from the gas flowing and entering the compressor used valve addition.

History, current state and outlook for developing Mesozoic complex of Terek-Caspian downfold deposits

The article is devoted to the outlook for oil and gas potential of the Mesozoic complex of the Terek-Caspian downfold. The problem of oil and gas content of great depths has been of interest to scientists and specialists since ancient times. However, it became especially relevant in the second half of the 20th century. With the depletion of the Miocene deposits of the Tersko-Sunzhenskaya oil and gas region being exploited for a long time in the 50s of the 20th century, the question of preparing new hydrocarbon reserves through the development of deep-lying horizons of the Mesozoic has become acute. The main oil production in the Tersko-Sunzhensky oil and gas region has been associated with the Mesozoic complex, in particular the Cretaceous one, for more than 60 years. In the Upper Cretaceous deposits, more than twenty highly productive oil deposits associated with a carbonate reservoir represented by fractured limestones were discovered. Currently, many deposits of the Cretaceous complex are at the stage of depletion. This article briefly covers the development of the Mesozoic deposits. As well, it assesses the current state of the oil complex of the Chechen Republic. The short-term and long-term prospects of oil and gas content associated with Cretaceous and Upper Jurassic deposits have been assessed. For successful operation, it is necessary to have a unified oil and gas production system, whose components are oil production, geological exploration and scientific research. Specific recommendations were given for conducting geological exploration for oil and gas. The article substantiates the necessity of studying the regional structure of the territory under consideration using a complex of geophysical methods and parametric drilling, in particular, aimed at studying the nature of the structure and composition of the Upper Jurassic deposits and determining the location and depth of parametric wells. It is recommended to focus on a number of regional seismic profiles for the study area.

Techno-economic analysis of a solar thermochemical cycle-based direct coal liquefaction system for low-carbon oil production

Direct coal liquefaction turns solid coal into transportable liquid fuel with a high energy conversion efficiency of nearly 60%. However, the hydrogen used in the direct coal liquefaction process mainly comes from coal gasification units, and gasification coal consumption accounts for about 30% of the total coal consumption. The authors of this article have proposed a solar thermochemical cycle-based direct coal liquefaction system and conducted a corresponding thermodynamic analysis. In this work, the economic feasibility, environmental impact, and the influence of key factors (coal price, oil price, carbon tax) for the industrial-scale low-carbon oil production system are analyzed. Compared with the traditional direct coal liquefaction system, the total coal consumption of the new system is reduced by ∼40%. Under low carbon constraints, the economics of the new system is comparable to that of the traditional one with a lower solar thermochemical hydrogen production cost (<13–16 yuan/kg H2). With the help of the solar thermochemical hydrogen production process, CO2 emissions of the new system can be reduced by 63%. Moreover, the solar thermochemical cycle could generate additional pure oxygen and profits. The methodology and results can provide important references for coal-to-liquid technology with high efficiency and low carbon emissions.

Simultaneous Control of Formation and Growth of Asphaltene Solids and Wax Crystals Using Single-Walled Carbon Nanotubes: an Experimental Study under Real Oilfield Conditions

Asphaltene and wax depositions in oil production systems have been recognized as the most serious flow assurance concern of petroleum engineering. Despite the several chemicals offered for treatment of issues induced by these organic deposits, proposing a single efficient chemical to control simultaneously both asphaltene and wax precipitation has not been attended yet. Here, single-walled carbon nanotubes (SWCNTs) were synthesized to assess their effects on controlling the formation and size growth of asphaltene particles and wax crystals in live oil under realistic production conditions. SDS experiments showed that during depressurization at 125 °C, the asphaltene onset pressure decreased from 5946 psi in untreated live oil to 4375 in treated live oil with 100 ppm SWCNTs. High-pressure microscopy revealed that SWCNTs efficiently controlled the growth of asphaltene aggregates and reduced the size of asphaltenes in live oil during depressurization at 125 °C. This is ascribed to the strong π–π interactions between the aromatic rings of SWCNTs and electron clouds of asphaltenes. Results of cross-polarized microscopy showed that SWCNTs at an optimum concentration of 75 ppm postponed the wax formation temperature and gelation point from 32.6 and 21.5 °C to 23.2 and 14.7 °C, respectively. In addition, the morphology of the wax crystals with an average size of 756 nm in untreated oil changed from dense spherical-like into thin needle-like with an average size of 86 nm in treated oil with SWCNTs at 75 ppm. The changes in the wax crystal size and structure via X-ray powder diffraction analysis after crude oil treatment with SWCNTs confirm interactions between the carbon nanotubes and active sites of the wax crystals. The findings of this research prove that synthesized carbon nanotubes can be used as efficient inhibitor and dispersant agents for stabilizing the waxes and asphaltenes in live oil with controlling the rate of aggregation under high-pressure–high-temperature conditions.

The impact of mono-ethylene glycol and kinetic inhibitors on methane hydrate formation

Rigorous quantification of hydrate formation probability in the presence of mono-ethylene glycol (MEG) is crucial for understanding hydrate formation risk in oil and gas production systems where the delivery of MEG for complete thermodynamic inhibition is either economically or practically infeasible. Using thermoelectrically cooled, stirred reactors, we have obtained 3,056 hydrate nucleation points in total. With these data we quantify the probability of hydrate formation in under-dosed MEG systems as a function of subcooling from the hydrate phase boundary, at MEG dosages between (5 and 25) wt% with respect to the aqueous phase. Although the addition of the MEG led to reductions in the measured formation temperatures, the corresponding subcooling distributions were similar to those measured in MEG-free systems. Furthermore, isothermal measurements at a fixed subcooling of (3.6 ± 0.1) K across a range of MEG loadings yielded comparable exponential induction time distributions. These results establish that MEG does not significantly affect either the nucleation rate or distribution of hydrate formation probabilities. Initial subcooling-dependent hydrate growth rates were also measured and reduced proportionally with the MEG dosage. Finally, we show how a low dosage kinetic hydrate inhibitor can be used together with MEG to further inhibit hydrate formation, by reducing both nucleation and growth rate. The results detailed here may be useful to the successful implementation of economically-viable, risk-based hydrate management strategies in under-inhibited systems.

Heterocyclic Compounds Containing N atoms as Corrosion Inhibitors: A review

Corrosion is the most important and costly cause of severe operational problems encountered in oil and gas production systems. It may occur anywhere in the production system, from the oil/gas well bottom to the final transfer of produced gas or oil to the refinery. Internal corrosion of carbon steel pipelines is a common and serious problem in oil and gas production, which is designed for long-term operation. It involves an interaction between the metal wall and the flowing fluids. This problem has caused the consideration of many corrosion control programs and research in various oilfields around the world. There is global use of carbon steels as materials of construction for pipes in the oil and gas industries. Compounds triazoles and their derivatives have attracted huge attention due to their simple preparation and superior corrosion inhibition activity towards mild steel in acidic environments. Therefore, the present review aims to highlight the carried out using Compounds triazoles and their derivatives for steel protection in different corrosive environments.

Expert solution for effects of input parameters on multiphase flow correlations

Oil and gas production represents an essential source of energy. Optimization of oil and gas production systems requires accurate calculation of pressure drop in tubing and flowlines. Many empirical correlations and mechanistic models exist to calculate pressure drop in tubing and flowlines. Previous work has shown that some correlations provide more accurate results under certain flow conditions, PVT data, and well configurations than others. However, the effects of errors in input data on the selection of which correlations to use have not been investigated. This paper studies different multiphase flow correlations to determine the effects of their input parameters on (1) the accuracy of calculated pressure drop and (2) the selection of best correlation. A database consisting of 33 oil wells and 32 gas wells was selected, and a commercial software was used to build different well models. A total of 715 well models were constructed and used to investigate the effects of errors in correlations inputs on both the calculated bottomhole pressure and the selection of best correlation(s). The methodology was based on perturbing the values of the selected input parameters and calculating the new predicted bottomhole flowing pressure. Then, the effects of error in input parameters on how the calculated bottomhole pressure was different from observed data were quantified. The effect of this error in input parameters was also checked against the algorithm that selects the best correlation(s). It was found that errors in input GOR have the greatest effects for oil wells, while gas specific gravity and the tubing roughness are the most effective parameters for gas wells. The results were integrated into a rule-based expert system. A new set of data, consisting of 220 cases from 10 new oil wells and 10 new gas wells, was used to validate the expert system. The expert system was found to predict the best correlation(s) with a success rate of 80%, and it also identifies the input parameters whose error would affect the value of calculated bottomhole pressure significantly. Finally, the rules of the expert system were programmed into a VBA-Code to ease its use.

Measuring Circularity in Food Supply Chain Using Life Cycle Assessment; Refining Oil from Olive Kernel.

Valorization of food waste is a potential strategy toward a circular food supply chain. In this regard, measuring the circularity of food waste valorization systems is highly important to better understand multiple environmental impacts. Therefore, this study investigated the circularity of a food waste valorization system (refining oil from olive kernel) using a life cycle assessment methodology. An inventory of an industrial-based olive kernel oil production system is also provided in this study. The system boundary was the cradle to the factory gate of the production system. The results indicated that natural gas consumption was the highest contributor to most of the investigated impact categories. The global warming potential of one kg of oil produced from olive kernel was calculated to be 1.37 kg CO2eq. Moreover, the calculated damages of 1 kg oil production from olive kernel to human health, ecosystem quality, and resource depletion were 5.29 × 10−7 DALY, 0.12 PDF∙m2∙yr., and 24.40 MJ, respectively.

Upstream-flow-based mechanisms for global flow regime transition of gas/liquid two-phase flow in pipeline-riser systems

In order to develop the transition models for undesirable two-phase flow regimes in a pipeline-riser system in offshore oil and gas production systems, the relation between the upstream flow condition in the pipeline and the global flow regime is analysed. The transition of local flow pattern along the upstream pipeline, especially the slug dissipation behaviour, is found to be related to global flow regime transition. The mechanisms for the transition from stable flow regime to different undesirable flow regimes are proposed separately. A set of hybrid criteria is established and validated by experimental data. The proposed criteria can predict the transition to undesirable conditions which are less severe but more common than the typical cases, compared with existing uniform criteria. The findings can help for better understanding of flow regime transition in a pipeline-riser system with more complex layout of pipeline, and also the possible extension of laboratorial experimental results.

Evaluation of a Jet-Pump for the Improvement of Oil-Water Flow in Pipeline Loops Using CFD Tools

Despite their low efficiency compared with centrifugal pumps, jet pumps are highly reliable, robust equipment with modest maintenance, ideal for many applications, mainly in the oil &amp; gas industry. Jet pumps are conventionally used to draw fluid from a storage tank in the petrochemical industry or as an artificial lift system to produce oil from a reservoir using energy from the primary fluid. The trunk lines in oil production systems can experience an unfavourable phenomenon due to the fluid's low velocities. In the case of transporting a heavy oil-water mixture with low flow velocities, it could promote oil and water stratification. Due to high viscosity, the stratified oil stick on the pipe,| causing a diameter reduction, resulting in a drop in fluids production and increased energy consumption. Given the virtue of jet pumps, this paper proposes using this equipment as an oil-water transfer pump as an alternative to expensive conventional multiphase pump systems. The jet pump will add fluid into the line, increase the fluid velocities, and promote the homogenous mixture of oil and water. Using ANSYS CFX, the effect of installing a jet pump in a conventional trunkline loop was analysed. Three jet pump configurations were simulated for different driving fluid pressures and compared against a traditional pipeline loop's performance. The first configuration shows a poor performance increasing only until 10% of handling fluids. Conversely, with the improved jet pump configurations rise of the fluid production by 30% has been obtained.

A Parametric Model of Umbilical Cable with Siemens NX considering its Reliability

Abstract Umbilical cable is one of the key control equipment, for example, in the subsea oil and gas production system. That can be seen as a customized product related to specific parameters of use cases, e.g. installation site. In this paper, we first apply the calculation method for the reliability of the umbilical cable by advanced first-order second-moment method (AFOSM) and Monte Carlo method. Secondly, we demonstrate the use of Siemens NX and its framework for engineering knowledge representation called Knowledge Fusion (KF) to generate the parametric model of the umbilical cable design considering its reliability. Finally, we reveal the advantages of introducing a Knowledge-based Engineering (KBE) approach to integrate the CAD models extended with automated calculations for product reliability.

Prospects of Breaking Crude Oil Emulsions Using Demulsifier Formulated from &amp;lt;i&amp;gt;Nicotiana tabacum &amp;lt;/i&amp;gt;Seed Oil, Leaf Extracts, and Stalk Ash Extracts

The presence of crude oil emulsions in oil production and processing systems has been a great concern to industry worldwide. Several methods are available for breaking crude oil emulsions; however, Chemical method is the common demulsification method. Fossil-based materials are mainly used to develop these demulsifiers. Given the recent environmental and sustainability concerns, focus has shifted to the use of bio-based materials like agricultural plant extracts as alternatives to fossil-based demulsifiers. In this study, the prospects of breaking crude oil emulsions using demulsifiers produced from <i>Nicotiana tabacum</i> seed oil, leaf extracts, and stalk ash were evaluated. The study is based on the need for local production of demulsifiers in Nigeria, the need for more environmentally friendly and sustainable operations; and the need to put <i>Nicotiana tabacum</i> into alternative use due to its associated health hazards when consumed and its massive cultivation. The results of the physiochemical properties of <i>Nicotiana tabacum</i> seed oil; the phytochemical analysis of Nicotiana tabacum leaf extracts, and the potash concentrations of <i>Nicotiana tabacum</i> stalk ash extract showed the presence of hydrophilic and hydrophobic components of demulsifiers. The properties of the formulated demulsifier are similar to those of the commercial demulsifiers. The bottle tests results showed that the formulated demulsifier is capable of breaking medium and high-density crude oil emulsions. Hence, the formulated demulsifier performed comparably to the commercial demulsifiers.

Evaluation of Velocity Impact on Sand Particles in Two-Phase Annular Flow in Horizontal Pipes

Experimental investigations on sand particles in annular flow in horizontal pipes were presented. The aim is to enhance the knowledge related to sand transportation in the oil and gas industry. More so, to add values in facilitating the optimum design of oil and gas production systems where annular flow is often encountered. The experimental investigations were conducted using a closed-loop consisting of a horizontal pipe with an internal diameter of 2-inch (0.0504m). The experimental investigations covered both: water/sand flow and water/air/sand annular flow. The water/sand flow experiments were carried out to establish sand transport regime in liquid such as sand saltation, sand streak, and sand suspension. While, water/air/sand annular flow experiments revealed that the only the only sand transport regime in annular flow are saltation and suspension. Sand concentration profile in the annular flows were also estimated by using the sampling method. It was found that the bigger the sand particle size (500microns) leads to higher concentration of sand being transported at the bottom of the pipe because of gravity effect, while the smaller the sand particle size (212microns), leads to the higher sand concentration. Also, the sand concentration increased at the gas core as the superficial gas velocity increases.

Definition of an oilfield production strategy through integrated simulation of manifolded production system and reservoir

This study presents an integrated simulation of reservoir and manifold-based production system for oil production and the influence of such equipment in oilfield management. The production strategy...

“Emergency Response Plan” Automated System for Oil Production and Transportation Enterprises

“Emergency Response Plan” Automated System for Oil Production and Transportation Enterprises

Optimal Resource Allocation using Distributed Feedback-based Real-time Optimization

Abstract This paper considers the problem of steady-state optimal resource allocation in an industrial symbiosis, where different companies share common resources. Such optimal resource allocation problems are commonly studied in the context of distributed optimization to limit information sharing. One such framework is the Lagrangian decomposition approach, where the different subproblems are locally optimized for a given shadow price of the shared resource, which is updated by a master coordinator. In the traditional distributed RTO approach, this involves solving numerical optimization problems online for each subproblem, which can be computationally intensive. In order to avoid the need for solving numerical optimization problems, this paper proposes a distributed feedback-based real-time optimization framework, where each subproblem is locally optimized for a given shadow price using feedback controllers. The proposed feedback-based distributed RTO scheme is applied to an industrial symbiotic subsea oil production system, where the different wells are operated by different companies. The simulation results show that the proposed feedback-based distributed RTO scheme can optimally allocate the shared resources.