bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Investigation on Effect of Enzyme and Nanoparticles on Oil-Brine Interfacial Tension
Authors: Hannah Tinuola , David Oyinkepreye
Published: August 2022

Interfacial tension (IFT) is an interfacial phenomenon that commonly exist between immiscible liquids such as oil and brine that are found in the hydrocarbon reservoirs. High IFT in combination with high capillary forces plays a fundamental role in residual oil saturation in the reservoir rock pores. The effects of enzyme and silica nanoparticles on crude oil-water and crude oil-brine interactions were investigated and presented in this study. The potential of individual application of enzyme and silica nanoparticles as well as the combination of both were explored under different salinity conditions. The results of this study showed that the application of silica nanoparticles did not significantly reduce oil-brine IFT under different salinity conditions investigated in this study, although the highest reduction was obtained with low salinity brine. The use of enzyme however significantly reduced oil-brine IFT under varied salinity conditions and better IFT reduction was obtained in brines relative to aqueous solution. Finally, the combination of enzyme with nanoparticles effected better IFT reduction than the application of either of them individually in aqueous solution and it also significantly reduced oil-brine IFT in all salinity conditions. This study is a novel investigation on the potential of enzyme-nanoparticles to modify oil-brine IFT and the result of this study is significant to the design and application of enzyme and nanoparticles enhanced oil recovery processes.
Integrated Reservoir Management in a Marginal Oil Rim Field
Authors: Uche Chukwunonso , Eremiokhale Obehi , Esieboma Samuel , Uche Jennifer
Published: August 2022

The field under consideration is located about 50 Km offshore Nigeria in water depth of about 130ft.

The field was discovered in 1968 with X1 well. This particular well encountered oil in four different zones (IX, X, XI and XII) in the Pliocene Agbada formation. The X1 well was logged and tested to evaluate the potential. The second well, X2 was drilled in the early 70s and that was in a separate fault block. This second well encountered oil in two reservoirs, IX and X. The XI was poorly developed in X2 well relative to X1 well which was found wet. The XII reservoir was encountered with good oil shows and gas readings were found in poorer sections of the reservoir. A third well was drilled which did not encounter any hydrocarbon and many of the sands were poorly developed or absent relative to the X1 and X2 wells. No testing was conducted in this well.

The field was appraised with X4 well. The X4 well encountered oil in all the four sands. Pressure and log data were taken from the reservoirs in this well and the well was tested to know the true potential of each. The reservoir sands are of good to excellent quality but are unconsolidated and sand control will be required in the development phase.

The fluid quality is 25 deg API with moderate viscosity and a moderate GOR in the XII, and about 14 deg API with high viscosity and low GOR in the other reservoirs. Reservoir pressure and temperature is normal in the IX sand, slightly over-pressured in the X sand and significantly over-pressured in the XII.

Following the successful results of the subsequent appraisal programme, the reserves level increased significantly to more than 40 MMbbls. At this level the field was judged large enough to support a stand alone development. This had allowed a first proposal to initiate an initial development plan for the Field. Development drilling commenced in 2009 with first oil was recorded in 2010.

As the development of the field progressed the lessons learnt from first development phase of drilling were implemented in the second phase. This led to better wells with improved production rates.

In addition, effective reservoir management in the field has led to optimized production which saw recovery factor in these oil rim reservoirs getting above 30%. This paper highlights the challenges encountered, innovative solutions and key learnings along each phase of development.
Enhancing Reservoir Stimulation through Mathematical Remodeling of Pre-Flush Acidizing Volume Algorithm for Different Reservoir Flow Geometries
Authors: Osuala Justice Chidera , Egu Daniel Ikechukwu , Ilozobhie Anthony John , Nwojiji Blessing Ogechi
Published: August 2022

Studies show that an average of 35% of reservoir acid stimulation operations executed every year fails because of limited knowledge of downhole acid placement. Existing models designed for acid pre-flush volumes are limited to Linear, Radial and Ellipsoidal reservoir geometries, therefore, do not account for geological drifts of a typical heterogenic reservoir. This can be erroneous while estimating acid placement volumes as reservoirs can deviate from defined flow geometries due to their dynamic and heterogeneous nature, thereby challenging to estimate acid volumes precisely for stimulations. This study aims to foster sustainability in reservoir flow engineering by deriving a mathematical model that evaluates volumes for reservoirs with flow geometries that deviate from linear and radial. This was established to help introduce a new geometry contributing to the accountability of complex and heterogeneous reservoirs. Sensitivity analysis and investigation using reservoir core data from SPDC Petroleum Chemistry Laboratory were carried out to understand the relationship between Linear, Radial and Modified flow geometries. Analytical results for linear, radial and the fied were generated. These results proved the precision of the modified equation for calculating pre-flush acid volume for reservoir acid stimulation operation.
Investigation of Permeability Impairment Using Local Polymers for Enhanced Oil Recovery
Authors: Uzoho Chidinma Uzoamaka , Ade Enaanabhel , Onyekonwu Mike Obi
Published: August 2022

The use of viscosity enhancer in Polymer flooding decreases mobility and improves sweep efficiency of flood water. However, there is a likelihood of permeability impairment due to the polymer retention onto the rock surface. This leads to formation damage. Therefore, a good assessment and evaluation of this problem is important to oil recovery sustenance. In this study, the permeability reduction caused by some local polymers in Nigeria used for Enhanced Oil Recovery was investigated. A laboratory study was carried out using unconsolidated core plugs (sands packs) and crude oil from the Niger Delta field. Two of the core plug samples (control samples) were flooded with simulated brine concentration and viscosity of 20000ppm and 0.949cP respectively. Cisus populnea (Okoho), Abelmoschus esculentus (Okro), Irvingia gabonensis (Ogbono) and Gum Arabic were used as polymers. Water breakthrough time, oil recovery and mobility ratio results obtained from fourteen samples were recorded and compared with that obtained from using only brine. The permeabilities of core plug samples were estimated prior to and after polymer flooding by pressure drop calculation. Residual Resistant Factor (RRF) and adsorption capacity of these polymers at same concentrations of 1000 ppm, 2500 ppm and 5000 ppm were also estimated. At 5000ppm, the RRF and mobility ratio for Cisus populnea, Abelmoschus esculentus, Gum Arabic and Irvingia gabonensis were 2.341/0.91., 1.354/0.35, 2567/0.56 and 3/0.66 respectively. The percentage reduction in permeability and displacement efficiency for Cisus populnea, Abelmoschus esculentus and Gum Arabic are 3.9%/75.30%, 2.7%/89.50% and 4.2%/77% respectively. It was observed that there was no-flow while flooding with Irvingia gabonensis at 5000ppm. The results from the study indicate that Irvingia gabonensis triggered the highest permeability impairment while Abelmoschus esculentus gave the least permeability impairment. The best performed polymer is Abelmoschus esculentus with highest displacement efficiency, reduced mobility ratio, lowest RRF values, lowest static and dynamic adsorption.
Polymer Selection for Enhanced Oil Recovery in a Niger-Delta Formation Via Laboratory Experiments
Authors: Dennar Linda , Amro Mohammed , Reichmann Sven
Published: August 2022

Several Scholarly articles have been written on the efficacy of Local and Foreign Polymers as agents of mobility control in Enhanced Oil Recovery Systems. Polymers are Non-Newtonian Fluids that are significantly affected by the reservoir properties. The Polymer chemistry is strongly dependent on Temperature and Salinity of injection/formation water thus the need for laboratory investigations of compatibility. Polymer solutions also undergo losses through adsorption and entrapment during propagation within the reservoir and subsequently create poor sweep if this happens.

This research has investigated the suitability of two Polymers in the Niger Delta Formation: Xanthan Gum which is a biopolymer and Polyacrylamide a Synthetic polymer. Using an Analogue core sample having similar properties with the "Case Study" and a 2.8g/l polymer concentration obtained via 3-Dimensional simulation model, a laboratory core flood experiment was performed. The essence of the flooding analysis was to investigate

The Residual Resistant Factor associated with the polymer solutions which is also an indication of the property changes associated with the reservoir post flooding. The benefits and economic viability of Polymer slug sizes with the addition of CO2 (Polymer Alternating Gas-PAG) was also investigated. Unsteady State single-phase permeability The Resistance Factor for the reservoir

Results from the 2.8g/l solution of Polyacrylamide flooding shows a favorable Residual Resistance Factor of 0.97 to 7.05. Indications from the results suggests that using smaller slug models would not be favorable for such deployments. Larger slug models yield better RRFs, while a combination of Larger Slugs + CO2 results in a more economic resource use as less polymer is deployed. 2.8g/l Xanthan solution though having good Rheology showed very high RRFs (75-124) suggesting a possibility of encountering injectivity issues. Further investigations will be required to ascertain the effects of reducing the concentration of Xanthan on the injectivity and generally on the recovery process.

A good handle on the concentration and chemical suitability of polymers with the inherent reservoir properties is the starting point of an efficient deployment of polymers as mobility control agents.
Deregulation of the Downstream Sector of the Nigerian Oil Industry and its Impact on Pump Price of Petroleum Products
Authors: Ekeinde Evelyn Bose , Dosunmu Adewale , Okujagu Diepiriye Chenaboso , Obazeh Dumbili Jerome
Published: August 2022

The oil industry is clearly the mainstay of the Nigerian economy, with revenues from the industry accounting for over 80% of the nation's foreign exchange as well as over 80% of GDP. Therefore, the importance of the petroleum industry to Nigeria's development and economic strength cannot be over stressed. This paper discusses the deregulation of the downstream sector of the Nigerian petroleum industry with emphasis on product pump price. Over the years it has been observed that despite the large volumes of revenue coming from the petroleum industry, the price of petroleum products continues in Nigeria continues to rise even with huge amounts of money spent on subsidizing product pump price to keep them affordable to the Nigerian people. The paper tries to analyse the concept of deregulation and how a well-planned and deregulation policy can be effected to achieved the desired goals of product availability and minimal pump prices. It proposes that a truly and fully deregulated downstream will not necessarily result in product pump prices that are lower than the current both in the short or long terms, but in a competitive market with many players compete resulting in product availability and competitive pricing. It puts forward that the government would have to put in place measures to curb corruption and collusion which might disparage on the successful deregulation of the subsector. It proposes that if the deregulation of the downstream is to yield best outcomes especially in product pump price then having an effective domestic refining capacity is very imperative which would include revamping the state owned refineries, issuing licenses’ for the construction of new refineries and operating them optimally. It recommends that the deregulation of the downstream must be gradual in order to achieve its desired goals
Economic Advantages of Emerging Indigenous Participation in Exploration and Production Operations in the Oil & Gas Industry
Authors: Ekeinde Evelyn Bose , Dosunmu Adewale , Okujagu Diepiriye Chenaboso
Published: August 2022

The study is a combination of survey and exploratory design. It utilized primary data (questionnaire) and secondary data (as journal, articles, industry reports and newspapers) with relative contents to the topic of discuss. The questionnaire was distributed to E&P workers in three LOCs, SEPLAT, Famfa oil and Yinka Folawiyo Petroleum. IOCs respondents from Shell, Total and Exon Mobil. Ten 10 questionnaires were distributed to each making 60 and 51 questionnaires retrieved and completed. The data gathered was presented using tables and analyzed using simple percentages, frequency and mean. The study concluded that participation of indigenous companies in exploration and production activities in the country has several economic advantages which both individuals and the government can benefit from. This includes increased production (barrels), increased Gross Domestic Product of the nation, job creation/ reduction of unemployment in the country and improved human resources due to training of indigenous worker. It recommended that the local content policy of 2010 should be taken more seriously by the government and more indigenous companies should be encouraged to go into oil exploration and production to increase the availability of crude oil products in the market which will automatically lead to better GDP, reduction in capital flight and increase in individual company income.
Environmentally Sound Technologies for Sustainability and Climate Change in Niger Delta
Authors: Oruwari Humphrey Otombosoba
Published: August 2022

This paper examines the concepts of environmentally sound technologies and sustainability. Environmentally sound technologies are potential ways capable of mitigating environmental pollution by adopting the use of energy efficient technologies. While sustainability is a process of change in which technological development and institutional change in which the exploitation of resource, the direction of investment, the orientation of technological development and institutional change are made consistent with future as well as present needs. In a broad sense sustainable development must enhance the long-term productivity of the resource base with acceptable environmental impacts. Using literature review and case studies of Britania U, a marginal oil field operator, Total Energy, and Shell Petroleum Development Company (SPDC). We find that environmentally sound technology can mitigate climate change. The study revealed that Britania used the technology which cleans out poisonous elements and emits smokeless air into the environment thereby mitigating climate change. Also, Total Energy, as part of its drive towards clean energy and reduce carbon emissions embarked on installation of solar energy while SPDC reported 17% decrease in routine flaring in 2020 due to the Southern Swamp Associated Gas Project which captured gas produced alongside oil in the Niger Delta. We find that environmentally sound technologies include all those technologies that reduce the negative impact of products and services on the natural environment. Furthermore, environmentally sound technologies have brought about increased opportunities for energy transition into cleaner forms of energy. We therefore recommend that developing countries try as much as possible to develop the internal capacities and embrace environmentally sound technologies to mitigate the negative consequences of climate change.
Investigating the biodegradation of hydrocarbons considering the principle and mechanisms of Microbial Enhanced Oil Recovery; its processes, its successes and current limitations
Authors: Okoro Franklin , Okpu Ambrose , Frank-Okoro Mary
Published: August 2022

The importance of biodegradation of hydrocarbon is numerous, including: waste water treatment contaminated by crude oil, and for microbial enhanced oil recovery (MEOR). Despite the latter (MEOR) being in use over a century now, it is yet to be widely accepted as an optimum large scale enhanced oil recovery technique in the oil and gas industry. An examination of literature reveals a large number of successful MEOR laboratory trials but with very few field applications. This is as a result of a lack of understanding of the mechanisms involved in MEOR. In this paper, an economic analysis of the various types of microbes was carried out in order to ascertain the type of microbes under the prevalent reservoir conditions that would yield an optimum oil recovery in terms of cost and time. The economic analysis conducted suggests that for short term projects, MEOR treatment may not be competitive economically compared with conventional EOR methods. However, for long term projects, MEOR is the most cost effective of all tertiary EOR methods and this is because, overtime, the effect of microbial activities within the formation increases due to the exponential growth of microbes, whereas in conventional EOR methods, the effect of the additives diminishes with time.
Microbial Enhanced Oil Recovery (MEOR): mechanism, rate of biodegradation of hydrocarbon, field applications and challenges
Authors: Okoro Franklin , Odukwe Patricia , Frank-Okoro Mary
Published: August 2022

This paper investigated the biodegradation of selected hydrocarbons (e.g., alkanes, such as decane, and others) by open mixed microbial cultures. Laboratory experiments were conducted with the aim to investigate the rate of biodegradation of dodecane using glass bioreactors over an incubation period of 31days. In the study, dodecane represented the hydrocarbon used, and the microbial activity was subjected to aerobic conditions. Mineral water was used to stimulate the microbial growth. The results obtained indicated that an increase in the rate of biodegradation can be achieved, thus resulting in an increase in the oil recovery efficiency. It can be inferred that MEOR is a "high-risk, high reward" process, depending on whether the microorganisms can produce oil recovery-enhancing chemicals by utilizing the residual oil within the reservoir as a carbon source. The high risk in this context refers to the severe constraints that the microbial system must satisfy in order to utilize an in-situ carbon source. The rewards however are that the logistical cost and difficulty in implementing the process is similar to those of implementing a waterflood.
Prediction and Prevention of Wax Deposition in MERO-006T: A Thermodynamic Modelling Approach
Authors: Nwosu Obiora , Daodu Olugbenga , Ogbunude Basil , Emelle Chima , Nnanna Erasmus , Emesi John
Published: August 2022

MERO-006T is an oil development well that was drilled and completed in the Q2100X reservoir. The well came into production in March 1988 and has been plagued with incessant wax build up leading to loss of oil production several times over a period of 17years.

Several wax cutting activities have been carried out to restore production in the well, however due to the frequency of wax build up leading to loss of revenue and the difficulty of the swamp terrain where the well is located, it became pertinent to adopt a more optimal, cost effective and long-term approach to address the frequent deferment caused by wax build up.

Research indicates that a wax inhibition tool (Silver HAWG) can be deployed in the well to address wax build up issue though historical deployment in some wells have not been very effective due to suboptimal installation depths in these wells. Hence, it became pertinent to determine the optimal depth for installation of the wax inhibition tool in MERO-006T.

This paper highlights the thermodynamic modelling approach adopted to determine the Wax Appearance Temperature in MERO-006T, the well modelling approach to estimate the depth which wax formation would occur and the optimal depth to place the wax inhibition tool based on lifecycle production expectations from the well. Installation of the Silver HAWG is expected to restore ca. 500 bopd, improve well availability by 30% and avoid biannual costs of ca. $2mln associated with repeated wax treatment in the well.
Digitalization of Old Generation Equipment for Field Operations Optimization
Authors: Adesina Eriagbaraoluwa , Olusola Bukola
Published: August 2022

Equipment such as generators and export pumps, among others are crucial in the continuous running of oil and gas operations in the oil field. However, this equipment can fail without prior notice leading to costly downtime, therefore; it is paramount to minimize equipment failure. The unpredictability of equipment failure leads to the repair time being prolonged due to difficulty in scoping and procuring the damaged parts. To solve this problem, we proposed the use of digital control systems and equipment telematics to be installed on analog generation units for data analytics and business efficiency.

In the proposed data acquisition strategy, the control systems interpret analog inputs, convert them to digital data, continuously monitor the data, and upload the data to a cloud database for seamless data transfer to data analyst. This data was used in evaluating the performance of the generators, identifying parameters that largely affects the efficiency of the analog machine and then the results were used in the optimization of field operations. Telematics devices convert analog readings such as current, voltage and gauges into digital data, send out event activity reports and receive commands can be installed in old analog equipment. For instance, fuel level sensors are placed in fuel tanks of generators to detect the volume as well as the rate at which the tanks are getting filled up and drained. The sensors also measure fuel temperature and quality. Fuel flow meters directly measure the engine fuel consumption, engine operation time and the fuel rate in the supply line from the storage tank to the generation equipment. In addition, a contactless reader reads and transmits engine parameters of the equipment - the Revolutions per Minute (RPM) of the machine, oil pressure, oil temperature, coolant temperature and other engine parameters to the cloud database storage.

The data collated is analysed with statistical methods and data analytical techniques. The engine parameters are weighted and used to determine the performance and the health level of the engine with all parameters being measured in real time. Based on the simulated training dataset and its respective results for each entry, generators can be predicted to be "healthy" or about to be faulty in real time. With this approach, old generation equipment and power output can be constantly monitored and connected to an event detection system.

This paper presents a way to digitalise old generation equipment, prevent power outages and prolong the life cycle of generation equipment in oil fields. Finally, the methods presented in this paper can be extended to any analog or old generation equipment requiring performance monitoring.
Managing Well Performance Under Reservoir Uncertainty: Case Study of a Niger Delta Well
Authors: Nnanna Erasmus , Nyeche Mofoluwake
Published: August 2022

Managing well performance under reservoir uncertainty requires robust definition of the operating limits of the well. It also requires flexibility for reacting to observed performance trends and adjusting the well operating envelope to guarantee safe operations and stable production. BAJE-8 experienced anomaly in production performance occasioned by exposure of part of the drain hole to a gas pocket near the gas cap. The well definition carried uncertainty in fluid contact and there was also inability to map intra-reservoir faults and shales around the proposed landing depth of the drain hole. Uncertainty in the size of the gas pocket also led to the inability to accurately predict the timing of the blowdown. Prudent reservoir management enabled by proactive well monitoring and surveillance led to timely review and modification of operating conditions of the well when abnormally high GOR was observed from the well. The strategy was to blowdown the gas cap while monitoring changes in the well parameters with expectation that parameters would normalize once the gas pocket is blown down. The GOR and FTHP showed a peak in performance and steadily declined within the 6-month period of blow down.

The blowdown pushed the well performance parameters towards the previously predicted ranges prompting modification of the operating envelope. This rollercoaster well performance occasioned by subsurface uncertainty lasted for some 6 months and was successfully managed. The well performance now aligns with predictions and the well has sustained production in the last 18 months.
A Finite Element Study of Integrity of Formation/Casing Annulus Cement Sheath in Niger Delta
Authors: Etoh Jessica , Dosunmu Adewale , Oriji Boniface , Moritiwon Oloruntoba
Published: August 2022

Cement sheath is a well barrier that prevents the unintentional and uncontrollable flow of fluids from, into a formation or back to its surface. However, during drilling and production operations, this cement is subjected to various stresses resulting from thermal stress, non-uniform geo-stress, compressive and tensile stresses. Therefore, this study describes a finite element analysis (FEA) simulation of a cement sheath of class G type under stress in a typical drilling and production scenario. With experiments, the rheological and mechanical properties of class G cement with varying water-cement ratio of 0.4, 0.5 and 0.6 were prepared and analyzed for their performance and workability. From the results, it showed that the cement system with the lowest water-cement ratio of 0.4, demonstrated the highest mechanical strength. This was attributed to lesser water in the mix triggering efficient interaction with cement. Hence, based on this study, 0.4 cement ratio is recommended if the ability to withstand compressive and tensile forces is desired. In cases where it is to be used for drilling and production operations characterised by fatigue and cyclic forces, its composition should be designed such that it is more ductile and flexible. An FEA software, ANSYS Mechanical APDL (ANSYS Parametric Design Language) was used to analyze stress to convergence. Material properties of 0.4 cement ratio was adopted for simulation based on experimental results. Also, well loading conditions were cycled at temperature and pressure of 0-104 0C and 250-290 bar simultaneously. Simulation results showed the time changes of equivalent (Von-Mises), maximum, minimum and shear stresses. Time changes of equivalent elastic strain, total deformation and stress intensity were also recorded. From the simulation results, it can be concluded that the yield point of the material occurred at a time (t) =1.3245×10−4 s under continuous stress. It is recommended that the contact point between the casing and the cement be monitored for deformation due to high stress response during stress analysis.
Developing a Model for Effective Cutting Transport Mechanism
Authors: David Oghenetega Shadrack
Published: August 2022

The transportation of cuttings and wellbore stability are indispensable in any drilling program. This is because a successful drilling operation is the key to a profitable business in the oil and gas sector, efficiency of cuttings transport is very important for a good drilling program, the transportation of these cuttings through the annulus is a complex problem that is affected by many parameters.

The objective is to design drilling mud for efficient cutting transport in different holes sections and develop a model that is more effective in lifting cuttings through the annulus without affecting the stability of the wellbore.

Cutting transport efficiency in vertical and deviated wellbore has been reported to depend on the following factors; hole geometry and inclination, average fluid velocity, flow regime, drill pipe rotation, pipe eccentricity, fluid properties and rheology, cuttings size and shape, cuttings transport velocity, slip velocity, etc., the accumulation of drilling cuttings in the wellbore causes several drilling problems. These includes an increase in torque and drag, which may limit drilling from reaching to a desired target formation, the analysis is carried-out using different cutting transport models like; larsians model, rubiandini's model, moore's model, Hopkins method and zeidler's slip velocity correlation.

This paper work is aimed at achieving a cutting transport model (I,e developing a model), that is more effective in lifting the drilled cuttings from the wellbore through the annulus to the surface after considering different existing cutting transport models and it is required that parameters affecting the efficient cutting transport are considered simultaneously.
A Review of Natural Polysaccharides as Corrosion Inhibitors: Recent Progress and Future Opportunities
Authors: Murungi Pearl Isabellah , Sulaimon Aliyu Adebayo , Ssembatya Oscar , Nwankwo Princess
Published: August 2022

Preventing and mitigating corrosion problems can be very challenging due to technical considerations and prohibitive economic implications. It is thus imperative to arrest the escalating corrosion rates and impede the deterioration effects of corrosion with versatile remedies. In this review, previous research efforts on the application of plant-derived polysaccharides as potential inhibitors of metal corrosion in various aggressive media are studied. The deployment of corrosion inhibitors has proven to be an outstanding solution to prolonging the lifespan of metals. However, the most applied inhibitors such as the inorganic and some organic compounds are prohibitively expensive, hazardous, and toxic. These limiting factors have stimulated interest in more research into greener and less toxic natural alternatives. Considering the success of synthetic polymers for corrosion inhibition, a wide range of plants with high natural polysaccharide content have been evaluated to determine their effectiveness as biodegradable, renewable, and more economical corrosion inhibitors. Studies generally show that natural polysaccharides exhibit over 90% efficiency for corrosion inhibition with appreciable adsorption on the metal surface. Modification and grafting of the plant polysaccharides to enhance their inhibition efficiencies and to make them more desirable are currently being investigated. Such bio-inspired polymeric molecules thus have invaluable significance as potential alternatives for the problematic corrosion inhibitors.
Oil Production Forecasting Models and Oil End-Use Optimization Framework under Global Energy Transition Dynamics
Authors: Gbakon Kaase , Ajienka Joseph , Gogo Joshua , Iledare Omowumi
Published: August 2022

This paper reviews oil (and gas) supply forecasting models and subsequently espouses atypical modeling approaches for the optimal allocation of crude oil production. This paper becomes imperative within the context of the global energy transition and the future of the oil and gas industry in Africa in general and Nigeria, in particular. A categorization framework has been utilized to classify oil supply forecasting models based on regional focus, modelling techniques, and outcomes. The log – log functional form is adopted in this paper to forecast oil production in Nigeria and subsequently optimize its allocation. A review of literature indicates that oil (and gas) supply forecasting has a long history and in recent times, there has been the tendency to rely on models that integrate engineering with economics. The models used to project oil and gas production to meet climate goals have now inputted environmental targets. This review of oil production forecast models is carried out against the backdrop of the need to optimally allocate Nigeria's future oil production to diverse uses. This will have impact on expected oil export earnings, domestic fuels’ imports, and the potential for petroleum products’ export earnings.
Economic Performance Review of Ghana's Jubilee Field: 2011-2021
Authors: Oppong Riverson , Aglina Moses
Published: August 2022

This research was conducted to review the economic performance of Ghana's Jubilee Field after more than a decade after the first oil in November 2010. The research conducted financial and operational analysis on Ghana's first discovered field, the Jubilee Field for the last ten years. The analysis included performance appraisal and qualitative evaluation of the Jubilee Field. The research question calculated the take of the project partners and ascertained the remainder of the programs contained in the plan of development for the Greater Jubilee Full Field Development.

The research shows that the Jubilee field project which was done in phases provided the contractor and partners opportunity to learn from each phase and improve upon subsequent phases. The economic performance of the field has been tremendous and provided a good return on investment for the partners. The payback period of the project was calculated based on the net cash flow to be barely five years after the first oil whilst government's total share was about 48% of the project rent. The take included royalties, taxes, additional oil entitlements and GNPC's equity share in the project while the contractor takes 52%. This was slightly different from what was calculated during the project economic analysis.

The research concluded that the project has a good return on investment and the phased approach in the execution was good for lessons learned to guide future projects and avoid some past mistakes. It was recommended among other things that the reservoir surveillance and jubilee southeast expansion which is part of the Greater Jubilee should be followed and executed according to schedule to improve the cash inflow for the project partners and government of Ghana.
Experimental Study on Gas Reservoir Pore Pressure Changes During Natural Gas Recovery and CO2 Storage in Porous Medium
Authors: Mohammed Nuhu , Abbas J. Abubakar , Enyi C. Godpower
Published: August 2022

Much research has been conducted to determine the impact of gas injection settings on residual natural gas recovery and CO2 sequestration. However, little research has been conducted on how reservoir pore pressure varies during natural gas displacement by CO2 flooding. Using a core flooding experiment, this article examined the effects of gas injections on reservoir pore pressure and compression ratio. A core flooding experiment was done at 30-40 °C and 1500 psig to investigate the effect of gas injections on reservoir pore pressure and compression ratio. The CO2 injection rate and N2 booster volume were adjusted to 0.2-1.2 ml/min and 8-36 cm3, respectively. Because of the turbulence effect, high mean interstitial velocity raises the molecular kinetic energy of the gas species, which subsequently influences the molecular agitation of the gas species and so alleviates reservoir pressure and gas compression. The typical CO2 injection experiments revealed substantial compression and pore pressure rises as the injection rate increased. The trial with N2 as a booster resulted in a steady increase, which explains their low dispersion coefficient value. As a result, there is less gas mixing and compression compared with typical CO2 flooding.
Dynamics of Heat Transport from a Reservoir to the Adjoining Formation in a Thermal Flood
Authors: Lawal Kazeem
Published: August 2022

Heat transfer from a petroleum reservoir to adjoining rocks is detrimental to thermal floods. While such thermal losses are inevitable, understanding the timescales of these heat exchanges would improve the design and management of thermal floods. Employing lumped-parameter system analysis and assuming series flow, this paper presents transfer functions that characterize response times of a reservoir and its surroundings to changes in temperature of the heat source. The reservoir-surrounding system is modelled as individual thermal capacitors and resistors. The transfer functions, solved for a step disturbance, describe the limiting case of negligible interaction between these subsystems. For a step-change in temperature of the heat source, responses of the reservoir and surroundings are simulated for some combinations of their properties. Simulation results explain time-delay between reservoir and surrounding temperatures. The time-delay is controlled by four distinct parameters vis-à-vis surroundings time constant (τr), reservoir time constant (τa), ratio of thermal resistances (R) as well as the ratio of conductive to convective heat flow (βr). These parameters are governed by petrophysical, transport and thermophysical properties of the heating medium, reservoir, and surrounding formation. It is shown that lag-time in thermal responses of reservoir and surroundings can range from few weeks to several years. For practical applications and analyses, these results provide insights into conditions under which a thermal flood may be approximated as adiabatic vs. non-adiabatic.
The Performance of Gum Arabic on Water-Based Drilling Mud at High Temperatures
Authors: Ajayi Florence , Adewole Steve
Published: August 2022

To drill deeper and consequently more hazardous wells and to exploit productive formation more fully, the drilling mud must have physical and chemical properties that will enable it to contend with greater variety of well conditions. The mud used in rotary drilling is one of the major factors in the success or failure of the drilling operation.

One of the challenges in drilling deep and ultra–deep wells is the negative impact on the rheological and thixotropic properties of the drilling mud when exposed to high temperature conditions. For a successful drilling operation, the drilling Engineer must have a good estimate for the values of rheological properties of drilling fluid, such as viscosity, density, yield point, gel strength and fluid loss.

In this work, laboratory experiment was conducted on water-based drilling fluid from ambient condition to very high temperature. Effects of elevated temperature up to 180°c on the rheological and thixotropic properties of the drilling fluid with Gum Arabic as a major additive.

Results show that mud density, viscosity and yield point are largely affected at Elevated temperatures for lower concentration of gum Arabic at Elevated temperature and pressures considered. However, with higher concentration of the Gum Arabic, carrying capacity is boosted, cation exchange is reduced, and total mud density is only slightly reduced at elevated temperature considered.

With this result, important information that can guide drillers of high pressure and temperature wells, to achieve safety and drilling efficiency with Gum Arabic as additive, is now available.
The Effect of Nano-Silica on the Properties of Water Based Mud Used in Drilling High Pressure High Temperature Wells
Authors: Jimmy Dorcas , Ogba Michael Ifeanyi
Published: August 2022

This study investigated the effectiveness of nano-particles, mainly silica, as an additive to water based muds to the extent of High Pressure, High Temperature (HPHT) conditions. Specifically, the study ascertained the impact of silica nano-particles in improving performance of water based mud, the study also investigated the effect of nano-silica on mud density and also investigated the quality of silica nano-particles as a fluid loss agent and rheology modifier. The laboratory study was divided into four parts: viscosity determination, fluid loss test, sand content determination, and density determination. All these studies were conducted using water-based mud with and without silica nanoparticles. In the course of the study, the rheological, fluid loss properties, the rheological behaviour of the mud, and the cuttings transportation efficiency were directly and indirectly ascertained. From the findings, it was ascertained that nano silica improves mud viscosity for plastic viscosity by 87.5%, the apparent viscosity of the mud by 6.8%, and mud density by 1.92%, and also reduces yield point by 2.9%, and fluid loss between 17.5% and 42.9% for time intervals of between 5 – 50 minutes in which the experiment was conducted for which harmonises and complements previous standardized researches done. With nano silica, the sand content of the drilling mud reduces. The presence of nano silica in drilling fluids decreases shear stress vs. shear rate readings which could reduce the pump pressure required for mud circulation in drilling operations. Based on these findings, it is recommended that future laboratory studies be done in dynamic conditions in order to investigate the effect of drill pipe rotation on cuttings transportation improvement for water-based mud without and with nano silica.
A Comparison of Tidal Signal Extraction and Bourdet Smoothening for Removal of Tidal Effect Induced Artifacts in Pressure Transient Analysis
Authors: Nnamdi David , Ochie Karen , Moghanloo Rouzbeh
Published: August 2022

The results of pressure transient analysis (PTA) are very important in reservoir characterization; however, this analysis can be affected by some non-reservoir behavior such as gas breakthrough, phase segregation in the wellbore, tidal effects, all of which can perturb the result accuracy. When data is acquired for PTA offshore, it can contain tidal effect, causing noise which can lead to misinterpretation when the test is analyzed, hence its impact should be accounted for in the analysis. Tides are experienced as the rise and fall of sea levels due to the variation in the earth's gravitational potential exerted by the moon and the sun, and the rotation of the Earth. Tidal signals have been observed to mask late time response for pressure build up tests and will significantly hinder correct interpretation of reservoir boundaries if left unaddressed. The effects of tidal pressure signals on the pressure derivative of pressure build-up tests are studied with the aim of comprehensively exploring the deviation from expected responses given known reservoir boundary conditions. Subsequently a refined method for pure tidal component removal from pressure derivative data is presented and compared to simpler Bourdet smoothening (L) and filtration of data points used in evaluation.

This work focused on an efficient method to analyze data containing tidal effects. The Bourdet derivative and log cycle filtration was effective in removing tidal signal effects on late time boundary identification with the drawback being having multiple possible interpretations of the IARF. Extracting the tidal signal gave a more defined IARF period and late time boundary effect period with only minor oscillations in the late time but the rigor of extracting the tidal signal without sufficient regional tidal information may prove to major hindrance to this process.
Unconventional Leadership: Development Opportunities for Young Professionals
Authors: Ukpohor Excel Theophilus
Published: August 2022

With increasing demand on human resource professionals to develop and groom young professionals under tight learning and development budget, unconventional leadership opportunities have to be explored as an option for leadership development. These are leadership opportunities that are not defined within the conventional organizational structures but are indirectly connected to organizational performance and deliveries. Exploring these opportunities provides the human resources practitioners a funnel through which they can deliberately develop young professionals within their organizations. They also provide a lens of leadership quality validation for these young professionals within the organization, thus reinforcing management investment in their leadership programs.

These paper examines the various unconventional leadership opportunities available to most oil and gas organizations in Nigeria. The paper also highlights how HR can effectively utilize these opportunities in the leadership development programs for young professionals and also highlights some of the risk associated with this methodology and potential mitigations.
Modification of Gas Lift Design in Dual String Producers Using Single Point Orifices in the Niger Delta
Authors: Adepitan Adekunle , Odedeyi Olalekan , Osifo Fred , Idehen Festus , Oluwafemi Olominu , Aminat Ayuba , Olanike Adeoye , Francis Oko , Bola Adelanke , Iginowari Green , Mojisola Aroyehun , Philip Ekpe
Published: August 2022

This paper outlines the systematic approach used to simplify and optimize gas lift operations in a dual string completion with a common annulus. Omicron 26 was initially completed as a dual string natural producer. The well was worked over in 2006 to abandon existing sands and recompleted on new reservoirs and at this point, dummy valves were installed in the tubing. The well had been flowing sporadically and naturally until the need to unload the annulus by carrying out a Gas Lift Valve Change Out (GLVCO) operation arose to maximize production from the well.
Numerical Simulation of Gas Injection for Condensate Revaporization in Gas Condensate Reservoirs. A Field Case Study
Authors: Ibe Alonge , Olafuyi Olalekan , Anim John , Etim Christopher , Ameachi Ntietemi , Olusola Bukola , Kpone-Tonwe Hannah , Obah Patrick
Published: August 2022

Gas productivity in a gas condensate reservoir declines due to the presence of two-phase fluid present near well bore due to bottomhole pressure lower than dew point pressure. This accumulated condensate reduces relative permeability to gas impairing flow rate and causing a reduction in productivity. This paper introduces a method of injecting gas into near wellbore region to re-vaporize the condensates and improve the permeability of gas and increase productivity.

This is achieved by conducting numerical simulations of gas injection techniques by comparing a no-injection case scenario and an injection case scenario. The effect of temperature and compositional effect of injected gas into the reservoir is analyzed, and its impact on increased productivity from the reservoir is recorded. The reservoir is modeled with an in-depth analysis of fluid phase behavior and composition and simulated using Compositional simulation tools from CMG.

Results from simulation shows an increment of about 7.5% increase in gas production and about 8% increase in oil produced at a temperature of about 200 deg F considerably higher than 2.4% and 4% gas and oil produced at lower injected temperature of 120 deg F. The above results are also dependent on composition of injected fluids.