The process of selecting a location to establish a modular refinery is just as intricate as designing one. Of the numerous factors and conditions to consider when siting a modular refinery, crude oil sourcing plays a vital role in refinery efficacy and profitability, with pressure drop in pipelines posing a significant threat. Other factors that are considered in the bid of siting a modular refinery include product market outlets, environmental and political factors as well as proximity to industrial hubs.
The subject of this paper is a modular refinery located in Kwale, Delta State, with a capacity of 20,000 bpd. The refinery receives the bulk of its feed crude oil from Bonny flow station, Niger Delta. The modular refinery also receives feed crude oil from the in-situ production from its marginal fields.
This paper entails a conceptual establishment of a common flow station from which six modular refineries with equal capacity of 20,000 bpd receive feedstock from. The six refineries are sited at different locations, with regular intervals of 10 km from the flow station.
The pressure drops along the six pipelines were independently determined after considering a host of factors and variables using the Darcy-Weisbach equation, Reynolds Number, Churchill Equation and the Colebrook Equation. From the pressure drop profile along each pipeline (consisting of the kinetic, friction and elevation factors), pumps are designed and installed to ensure optimum performance of the pipelines.
The financial data (cost of construction of buried coated pipe, cost of screw pumps) used to carry out the economics of this project was obtained from Chevron Nigeria Limited, Piping Department, 2016.
The total capital cost needed to establish the modular refineries were plotted against flow station-refinery distances. From the plot, a model was developed to accurately determine the variation in the cost of establishing a modular refinery for every kilometer it is sited away from the source of the crude oil, keeping other factors such as the chemical composition of the crude being transported or the operational conditions of the network constant.
It is a general rule of thumb that the closer a plant is to its source of feedstock the more efficient and economical it would be. This paper helps to accurately determine how critical the flow station location could be as a factor in the siting of a modular crude oil refinery.
Otombosoba, Oruwari Humphrey (Institute of Innovation, Technology and Engineering Management, University of Port Harcourt-Nigeria) | Dosunmu, Adewale (Department of Petroleum and Gas Engineering University of Port Harcourt Nigeria Stanley Buduka, Energia Limited Nigeria)
Economic, environmental, natural, socio political, technological and other man made circumstances aggregate into sources of risk which result in the main constraints to sustainable development of marginal oil fields in Niger Delta region. For marginal oil fields, the constraints may further reduce the economic viability as well as result in devastating consequences to the environment. The paper examines the causes of the main constraints to marginal oil field development and the associated consequences in Niger Delta region. The identification of the main constraints to marginal oil field development presents opportunities for continuous improvement and possible reduction in the cost of operations of the marginal fields in Niger Delta region. The study provides new information that is not publicly available for Niger Delta region and serves as a useful guide for investors wishing to participate in the sustainable development of marginal oil fields in Niger Delta region. Adopting an innovative methodology, involving literature and document analysis the study identifies economic condition, know-how and institutional capacity as the key constraints in sustainable development of marginal oil fields in Niger Delta region. Although security concerns are significant with outlying step influences, however, we also established that other non-technical factors result in the main constraints to marginal field development among which are funding, technical expertise, government policy and marginality of the field. The solution lies in addressing these burning issues. The paper provides a strategic management model for sustainable development of marginal oil fields in Niger Delta. The proposed model can be applied as input into a wider risk assessment framework for investment decision.
Almost always crude oil is produced in conjunction with associated gas and for the type of reservoir considered in this study, gas production rate over time increases with decreasing pressure. The problem of maimizing production and/or recovery can be addressed by adopting an innovative, multi-stage separation technique. We use theoretical analysis and the latest version of Aspen HYSYS to demonstrate process plant optimization of a real case study of a separation facility in Nigeria's Niger Delta area with the objective to achieve higher plant profitability than those achieved by current practice. Based on the estimation of the optimum separator pressures for a 48,470 bbl/day crude oil and 50.27 MMSCFD gas production facility, it is found that crude oil and associated gas recovery increased by 1,620-bbl/day and 0.21 MMSCFD, respectively. Compared to current practice at the facility, a yearly average of fourteen million US dollars would be realized by our improved multi-stage separation method.
Eyitayo, Stella I. (First Exploration & Petroleum Development Company) | Lawal, Kazeem A. (First Exploration & Petroleum Development Company) | Ukaonu, Cyril E. (First Exploration & Petroleum Development Company) | Ovuru, Mathilda I. (First Exploration & Petroleum Development Company) | Sanyaolu, Adeniyi A. (First Exploration & Petroleum Development Company) | Otubanjo, Modupe A. (First Exploration & Petroleum Development Company) | Olushoga, Elizabeth O. (First Exploration & Petroleum Development Company) | Matemilola, Saka (First Exploration & Petroleum Development Company)
Encountering a reservoir in either a gas-down-to (GDT) or an oil-up-to (OUT) situation poses a challenge to development planning and reservoir management. The resulting uncertainties in the distribution, in-place and recoverable volumes of oil and gas may jeopardize expeditious execution of the field development project. To confirm the presence or absence of either oil or gas and establish a possible gas-oil-contact (GOC), in some cases the drilling of an appraisal wells(s) may be required. This paper describes a method that does not depend on dedicated appraisal wells to reduce GOC uncertainties and proves to be a valuable method to de-risk planned reservoir developments.
Where credible pressure-volume-temperature (PVT) data are available from the subject reservoir, compositional-grading simulations (CGS) can be employed to evaluate the presence (or otherwise) of a GOC within a vertically continuous reservoir column. From a thermodynamic standpoint, the GOC is that depth at which the reservoir fluid transits from being gas-like to oil-like, and vice-versa. Considering some saturated and undersaturated oil reservoirs in the Niger Delta as case studies, this paper demonstrates the applicability of a combination of PVT and CGS to de-risk the presence of GOC without resorting to either a new well or a pilot hole.
In the cases where well logs have established GOC, blind tests show excellent agreement between CGS results and well logs. Similarly, CGS accurately suggests the absence of gas-like fluids within the proven undersaturated oil reservoirs examined.
Finally, the results of this study will document that CGS is reliable and cost-effective for reducing GOC uncertainties and de-risking field development projects. Consequently, this method is recommended whenever credible PVT data are available.
Ndokwu, C. (Baker Hughes) | Okowi, V. (Baker Hughes) | Foekema, N. (Baker Hughes) | Wharton, P. (Baker Hughes) | Brock, P. (Baker Hughes) | Holbrough, D. (Baker Hughes) | Ndefo, O. (Total E & P Nigeria) | Agbejule, A. (Total E & P Nigeria) | Delpeint, A. (Total E & P Nigeria)
Variable reservoir thickness, heterogeneity, and presence of geological truncations are some of the challenges inherent in draining complex reservoirs. These challenges affect the depth of detection of some formation evaluation tools, the ability to optimally place the well in the target horizon, and the ability to remain in the sweet spot throughout the drain length. To mitigate these challenges, reservoir navigation service with fit-for-purpose tools and robust software is required.
This paper is a case study of the application of the VisiTrak™ tool and Multi-Component-While-Drilling (MCWD) inversion software (
The successes recorded in this geosteering case include accurate subsurface structural interpretation, reservoir characterization, and achieving well objective in terms of net sand drilled. This paper demonstrates the importance of reservoir navigation in accurate well placement, the benefits fit-for-purpose tools bring to geosteering complex reservoirs in the Niger Delta and shows the value of data integration in reservoir navigation service.
Nigeria aims to stimulate its economy by taking advantage of its gas reserve base to drive power generation and industrial growth. Several steps have been taken to achieve this. The study aims to identify the impediments to the desired results and proffer solutions to fast track the implementation of existing policies and structures.
To identify the current challenges militating against fast tracked gas development for the economic benefit of Nigeria, one needs to appreciate the successes gained so far by the nation. The gas industry pre development of the Nigeria LNG Project is considered. National power generation data is presented pre and post the advent of gas generating power plants. National gas demand data over a 20 year period is analyzed and compared to reserve growth. Gas midstream infrastructure pre and post approval of the Nigerian Gas Master Plan (NGMP) in 2008 is identified and compared. Effects of implementation of the commercial frameworks for upstream development and the Gas Master Plan are also analyzed.
Although a lot of successes have been recorded by the country, certain impediments have hampered the desired national economic growth. The following although still existing, are being addressed by the various stakeholders; Gas supply issues PSC Gas Terms Funding challenges Non alignment of priorities by NNPC's different JV partners Community issues Security issues Competing projects by prospective investors Non passage of the PIGB Policy somersault
Gas supply issues
PSC Gas Terms
Non alignment of priorities by NNPC's different JV partners
Competing projects by prospective investors
Non passage of the PIGB
The paper analyzes the challenges and proffers innovative solutions towards addressing the issues. These solutions will not only help to provide a different line of thought for policy makers and other stakeholders in the Nigerian oil and gas industry but will also provide a sort of "lessons learnt" for other developing countries with recent oil and gas finds to fast track the development of their gas industry thereby achieving the desired economic growth.
Balogun, Olalekan (The Shell Petroleum Development Company Nigeria Limited) | Alli, Adem (The Shell Petroleum Development Company Nigeria Limited) | Ogbuli, Andrew (The Shell Petroleum Development Company Nigeria Limited) | Apampa, Yewande (The Shell Petroleum Development Company Nigeria Limited) | Bahry, Alia (The Shell Petroleum Development Company Nigeria Limited) | Fasasi, Roseline (The Shell Petroleum Development Company Nigeria Limited)
While the development of retrograde gas-condensate fields is usually targeted at supplying medium to long-term contractual obligations, their profitability is significantly influenced by the ability to maximize condensate (C5+) recovery. This, however, is impacted by the retrograde condensation phenomenon where condensate drop-out in the reservoir during depletion results in loss of huge amounts of valuable liquids, which reduces the effective gas permeability and overall reservoir productivity. One of the ways to manage the impacts of this phenomenon is via Gas Recycling.
Horner Field is located onshore Niger-Delta and has two prolific overpressured reservoirs, G1X and G2X. G1X reservoir is a lean gas reservoir with initial CGR of 51stb/MMscf. G2X reservoir is a near critical fluid with a CGR range of 188 to 280stb/MMscf with depth, suggesting a compositional grading system. The potential production challenge in G2X reservoir is retrograde condensation in the reservoir coupled with water encroachment. The Constant Volume Depletion (CVD) Experiment from the PVT Laboratory Study indicates maximum liquid dropout of 6% at reservoir pressure of about 2000 psia in G1X reservoir and 40% at reservoir pressure of about 4000 psia in G2X reservoir, thereby making G2X reservoir a potential candidate for enhanced condensate recovery.
This paper presents overview of an assessment of the potential benefits of gas recycling in Horner Field using full compositional dynamic and integrated production models. Six development wells were found to be optimal for Horner field development. Sensitivities on injector optimum location and well counts were carried out. While the natural gas (mainly methane) from G2X reservoir was being recycled into thesame reservoir, the wells in G1X reservoir were beaned up to ensure security of gas supply obligation. 1-injector Scenario was found to be optimal with incremental condensate recovery factor of about 8%and positive economic indices of 15.2% IRR.
Ogolo, Naomi Amoni (Institute of Petroleum Studies, University of Port Harcourt) | Wobo, Monica Aleruchi (Laser Engineering and Resources Consultants) | Onyekonwu, Mike O. (Department of Petroleum Engineering, University of Port Harcourt)
Enhanced oil recovery (EOR) using carbon dioxide (CO2) has proved to be successful in some oil producing regions of the world, but this method has not been implemented yet in the Niger Delta. Crude oil swells when mixed with CO2; this makes the oil light and causes it to flow more easily within the reservoir. This work thus investigates the prospect of using CO2 for EOR in the Niger delta by simulating the outcome with three depleted reservoirs in the region under full water drive, partial water drive and volumetric drive mechanisms. The reservoirs were produced until production was no longer economical, necessitating external support. The life of each reservoir was extended for a production period of twenty years after its economic life under four simulated scenarios. The first was continuous production from each reservoir under the natural drive mechanism to serve as the reference case. The second scenario involved water injection while the third entailed injecting CO2 into each reservoir for twenty years. The fourth method was still CO2 injection but with intermittent water injection; the water alternating gas (WAG) method.
Very significant improvement in terms of oil recovery factor was observed with the reservoir under partial water drive and fluid expansion mechanisms. The reference, water injection, CO2injection and CO2 WAG scenarios for the reservoir under partial water drive mechanism yielded 40%, 63%, 56% and 65% respectively. For the reservoir under volumetric depletion, the reference, water injection, CO2injection and CO2WAG had 33%, 63%, 58% and 61% respectively. There was also improvement for the reservoir under full water drive mechanism with the use of CO2 but it was not very significant probably because full water drive mechanism for oil recovery is efficient and would have effectively swept the reservoir of its recoverable oil.
Adejoke, Adebayo (The Shell Petroleum Development Company Nigeria Limited) | Hamzat, Kassim (The Shell Petroleum Development Company Nigeria Limited) | Laoye, Abiodun (The Shell Petroleum Development Company Nigeria Limited) | Cosmas, Nwankwo (The Shell Petroleum Development Company Nigeria Limited) | Iyengumwena, Ricky (The Shell Petroleum Development Company Nigeria Limited) | Nnadi, Magnus (The Shell Petroleum Development Company Nigeria Limited)
Smart well technology allows production acceleration from multiple completions and value realization from otherwise marginal reservoirs. Critical to the success of a smart well completion targeting more than one reservoir is the proper design selection and reservoir isolation to prevent cross flow.
This case study describes the selection of a suitable gas well design from different available options, the considerations made in the design selection which incorporated the different completion components, one of the components being the feed-through swell packers which is its first use in the company, to achieve reservoir isolation. The paper also describes the execution of the selected completion design in one of the cases, as well as the testing of the well to verify reservoir isolation, and confirm the effectiveness of the feed-through swell packer.
The selected completion design was cost effective, reduced operational / deployment risks (compared to other isolation options) and had no adverse impact on well productivity of the wells. It also achieved the objective of accelerating the recovery of a combined volume of 221 Bscf of gas from marginal gas reservoirs in a field.
Ibemere, Uche (Laser Engineering and Resources Consultants Limited, Port Harcourt, Rivers State) | Mmata, Bella (Laser Engineering and Resources Consultants Limited, Port Harcourt, Rivers State) | Onyekonwu, Mike (Department of Petroleum Engineering, Unversity of Port Harcourt, Rivers State)
Crude oil fingerprint analysis is an investigative technique which can be employed during exploration and production to yield useful geochemical parameters, needed by the geologist, production engineer and oil spill management specialist. This analysis can give clues on depositional environment, thermal maturity, oil biodegradation and even aid production allocation.
In this work ten crude oil samples from the Niger Delta region of Nigeria were analyzed. The analysis was done with Gas Chromatographic instrument equipped with flame ionization detector (GC-FID) and HP-PONA capillary column. The standard method used was based on ASTM D2887. In-house developed mathematical tools, such as star diagrams and production allocation graph were used to estimate the required geochemical parameters.
The results of the analysis suggest that 50% of the analyzed samples were from oxic paleoenvironment which their ratios (above unitary (1)) indicated; 70% of them have predominance of odd carbon in their make-up, with carbon preference index (CPI) value above 1, while 60% of the analyzed crude oil samples were thermally immature. The outcome of this work can be used to estimate production allocation quota, identify culprit sample in time of spill incident and dispute between operators in a cluster area. Furthermore, it is an economical means of crude oil characterization when compared to other techniques.