bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving the reliability of Surface Production Facilities in the Oil and Gas Industry through better data quality
Authors: Ehi Ataga , Asiodu-Otughwor Isioma
Published: July 2015

Surface production facilities refer to all the equipment used in the oil and gas industry to separate and measure the produced fluids from hydrocarbon reservoirs (oil, gas, water, and impurities), prepare the oil and gas for transportation to the market, and handle disposal of any water and impurities. Examples of this equipment include compressors, pumps, separators, metering systems, coolers, pipelines, storage tanks, turbines etc.

The reliability of surface production facilities refer to the ability of the above named equipment to perform its required function under given conditions for a given time interval.

Equipment failure history over the entire facility life cycle is the key component of reliability data for surface production facilities. Quality reliability data would contain the following: detailed description of fault, functional location to lowest possible level, accurate maintenance planning group and work centre, damage information(such as object code, part code, damage code), symptoms, execution condition (whether it is done on the run or during a shutdown), and appropriate corrective maintenance priority rating.

Reliability data is deemed to be of high quality if they are fit for their intended uses in surface production operations, decision making and planning as well as if they correctly represent the real-world construct to which they refer. These data are useful for planning, front end loading for new projects, equipment improvement initiatives/minor modification projects, decision making, budgeting and business improvement initiatives/projects.

Good quality reliability data will safeguard the integrity of the facilities (which is a core aspect of asset integrity and process safety management), improve maintenance performance, reduce the direct cost of maintenance, and minimize downtime thereby increasing productivity. Therefore good quality information is paramount to maintenance improvement and translates to improved equipment reliability.
Biological And Chemical Changes Associated With Exposure Of Cyprinid Fishes To Some Oil Field Chemicals In The Niger-Benue River System, Nigeria
Authors: Uche A. O , Sikoki F. D. , Konya R. S.
Published: July 2015

Oil and gas exploration and production in Nigeria is geared towards meeting the energy need of its populace and also generate revenue. However, oil field chemicals used in oil and gas activities are sources of environmental pollution, causing various degrees of harm especially to the aquatic components of the environment. Most ascertained detrimental effects of oil field chemicals on organisms are generally laboratory based investigations. These have not considered synergistic and antagonists effects of these chemicals under various environmental conditions on organisms and the ecosystem. A research that incorporates both field and laboratory studies to investigate the effects of oil field chemicals in the natural environment would be of great use to provide a wholistic data for scientists. Such research would consider both synergistic and/or antagonistic effects of these chemicals under the natural environment with its varing conditions. The result obtained from such study would significantly enhance - integrated catchment management (ICM), further limnological studies/assessment, information for policy redress on contamination and pollution abatement, and remedial activities to ensure a sustainable healthy environment.
Biosurfactant production from Palm Oil Mill Effluent (POME) for applications as oil field chemical in Nigeria.
Authors: Hope Neboh , Gideon Abu
Published: July 2015

The interest of Petroleum industry in biosurfactant production has increased considerably in recent years as a possible replacement for chemical surfactants which are known for their high toxicity and non-degradability. Biosurfactants are amphiphillic surface active agents produced by microrganisms. They are biodegradable and have been found useful in oil field applications such as bioremediation of hydrocarbon impacted media due to their enhanced oil recovery ability, solubilisation, removal of oil from contaminated soil and sludge in oil storage tanks, dispersion of oil spills, transfer of crude oil and bioremediation of recalcitrant molecules without a residual toxic effect on the environment. These properties make their usage more advantageous over their synthetic counterparts. Biosurfactants can be obtained with the use of agro-industrial waste such as Palm Oil Mill Effluent (POME) as substrate, this helps to reduce overall production costs. Microrganisms have demonstrated the ability to utilize POME as a carbon source accompanied with biosurfactant production. This is due to their unique metabolic pathways which makes them a useful tool in the bio-industry. Production of biosurfactants from POME will not only reduce its production cost but will also encourage the use of our indigenous raw material thus reducing the amount of waste released into the environment and contributing immensely to sustainable waste management. The present review describes the production of biosurfactant from POME and its applications in oil field industry.
Mitigation of Biogenic Sulphide Production by Sulphate Reducing Bacteria in Petroleum Reservoir Souring
Authors: Immanuel O. M. , Abu G. O. , Stanley H. O.
Published: July 2015

Sulphate-reducing bacteria (SRB) often thrive in reservoirs requiring seawater flooding to enhance recovery of oil. A mix of sulphate ions, easily degradable organic compounds and SRB, coupled with a favourable temperature, leads to biosulphidogenesis. Petroleum reservoir souring occurs when there is an increase in the concentrations of hydrogen sulphide in produced fluids. Physiological and molecular studies have given us the picture of microbial diversities in petroleum reservoirs, tolerable conditions for their growth and metabolism, and the presence of genes for various metabolic functions. Uncontrolled growth of SRB limits reservoir productivity due to bioclogging and can also lead to biocorrosion, increase in the refining cost and decrease in the economic value of crude, due to biogenic sulphide production. The decision to control the activities of SRB is one that must be taken before the onset of souring. The use of green biocides such as glutaraldehyde and tetrakishydroxymethyl phosphonium sulphate (THPS) has proven effective. Less expensive and environmental friendly biocides effective against both sessile and planktonic SRB growth are sought by the petroleum industry as alternatives to those currently in use. Here, we review the role of SRB in petroleum reservoir souring, mechanisms of souring and biocorrosion, souring mitigation strategies, and recent advances in control of SRB.
Managing Greenhouse gases emission through minimizing the usage of blanketing gas on storage tanks – The Bonny Oil and Gas Terminal Case Study
Authors: Ehi Ataga
Published: July 2015

Greenhouse gas emissions are primarily responsible for the greenhouse effect, which occurs when thermal radiation from the earth surface is absorbed by these greenhouse gases and radiated back to the earth surface. The consequence of this phenomenon is a rise in the average earth surface temperature. It is established that the earth's natural greenhouse effect makes living on earth possible and comfortable for humans but the activities of humans such as burning of fossil fuels(hydrocarbons) over time has intensified the natural greenhouse effect by significantly increasing the atmospheric concentration of carbon dioxide resulting in global warming. Global warming has resulted in widespread melting of snow and ice, sea level rise, increased humidity, and increased heat content of the oceans.

The Bonny Oil and Gas terminal receives, dehydrates, stabilizes, stores and exports all crude oil produced in SPDC Eastern operations and the processed crude oil is exported by pipeline to tankers and to the nearby NNPC refinery. In the Terminal, LP fuel gas (composed mainly of methane) is used as blanketing gas and is introduced into storage tanks and vessels to prevent a vacuum from developing when liquid is removed from a tank to maintain the desired blanket pressure and prevent outside air from contaminating the tank or creating a flammable or explosive environment. It also ensures that a constant gas pressure is maintained in the vapour space of a storage tank.

Efficient blanketing gas demand would ensure that pressure relief from tanks and vessels which ultimately result in greenhouse gas emissions are minimized. This is implemented through the use of split range control scheme for blanketing gas on fixed roof storage tanks in the Export Terminal. In a split range control scheme, the output of the controller is split and sent to two final control elements (pressure control valves).The splitter is configured to define how each pressure control valve will open. The first valve which allows inflow of blanket gas to the tank opens when the output is of the range 0-45% while the second pressure control valve to the flare opens at an output range of 55%-100%.

The deployment of this control scheme of blanketing gas on fixed roof storage tanks in Bonny Terminal has resulted in the lowering of greenhouse gas emissions, combating climate change, process optimization, and significant energy savings.
Improving Value by Leveraging on Integrated Multi-discipline Data Review for a Partially Appraised Gas Field Development: The Zed Field Case Study
Authors: Sonde Adenike , Ozoemene Uchechukwu , Nwabudike Udoka , Ifeanyi-Onah Florence , Amuboh Okiemute , Esho Muyiwa
Published: July 2015

The importance of multi-discipline integration in the various phases of hydrocarbon exploitation cannot be over-emphasized. In the past, the various subsurface disciplines, within the oil and gas industry, worked in silo-like organizations which often results in a sub-optimal understanding/evaluation of the subsurface data. However, in recent times, much has been done and written on multi-disciplinary integration and its benefits particularly with respect to subsurface studies.

The Zed field, which is the subject of this paper, is a predominantly gas bearing partially appraised field. The field is composed of a series of stacked sandstone reservoirs located in the Niger-Delta Region of Nigeria. Given the limited subsurface data available within the hydrocarbon-bearing areas of the field (only 2 of the 6 wells in the field penetrated the hydrocarbon-bearing sections), one of the biggest challenges of developing this field remain the high level of subsurface uncertainties coupled with the potentially low economic value of further appraisal and development of the field. In order to adequately assess these uncertainties and the economic feasibility of developing the Zed field, a detailed subsurface study involving a full re-evaluation of all potential hydrocarbon bearing sands penetrated by the wells was required.

The study, which kicked off with a comprehensive integrated multi-discipline data review and quicklook evaluation, resulted in the identification of two additional reservoirs previously considered too marginal to contain substantial hydrocarbon. This paper details how the systematic, multi-discipline data integration and review of these two reservoirs helped in the identification and determination of higher hydrocarbon volumes in these reservoirs; and how this has helped in improving the economic value of the Zed field development project.
Wellbore Strengthening through Squeeze Cementing: A Case Study
Authors: Ogochukwu Benyeogor
Published: July 2015

Formation strength is an important parameter in drilling operations pressure control because it indicates the wellbore pressure containment envelope above which fracture or rock matrix failure starts to occur and propagate if the pressure/stress is sustained. The rock mineralogy, the orientation of wellbore with respect to the direction of regional fault line, the stress regime as well as the permeability of the rock determines the manner in which the rock would fracture. During well operations, situations that may result in the fracture of one of the formations traversed by the wellbore could arise, in which case, the main operations focus shifts to ensuring that the fractured formation is repaired before normal well operations can resume. One of the techniques of reinforcing or repairing a fractured formation is Wellbore Strengthening; which employs a variety of technologies such as deployment of resins and specially designed cement slurry.

Over the years squeeze cementing success has greatly improved through studies and using best practices; however, wellbore strengthening through squeeze cementing still poses unique challenges of determining the location of the fractures that need sealing; and also whether these fractures are compatible with the designed cement slurry. Thus squeeze cementing, while being economical and effective, will only succeed if the job is properly designed and executed.

This paper will demonstrate, through actual results, the feasibility of squeeze cementing as a means to restore wellbore strength by explaining the basic engineering that goes into designing a successful squeeze cement job for this purpose. It focuses on describing how the multidisciplinary approach of rock geo-mechanics, lithology, fluid mechanics, cement slurry design and proper job execution can contribute to the success of wellbore strengthening through squeeze cementing.
Strategic Management of Health Safety and Environment Risks in Down-Trodden Oil Dependence Economy
Authors: Tubosun Fagbe
Published: July 2015

As price of crude oil descends with fast falling economy of some oil dependence national economies like Nigeria, strong indications have emerged that the management of Occupational Health, Safety and Environment in Nigeria Oil sector may nose-dive due to shortage of funds, company's income, national currency exchange rate, management preference for profit, inadequate risk analysis, government policy and standard enforcement challenges. This paper examines the various factors that may negatively and positively affect safety management in suggesting strategic health safety and environment management styles that may trigger, maintain and sustain business corporate image, improvement in productivity, returns-on-investment, reduce accident, eliminate cost of litigation and victim compensation despite national economic crisis arising from crash in International Crude Oil price.
An Investigation of the Effects of High Temperature and High Pressure (HTHP) On the Stability of Wellbore Casing Using Finite Element (FE) Method
Authors: Ohenzuwa S. O , Olafuyi A. O , Nwankwo E. , Bello K. O
Published: July 2015

Casing is designed to provide well bore stability and withstand imposed loads such as external pressure, internal pressure and mechanical load due to compressive forces on casing. To ensure integrity and reliability of casings, a cost effective approach is hereby presented using finite element (FE) methods.

At ordinary conditions of temperature and pressure, casing design can be achieved by the use of available grades of casing, but for HTHP wells it becomes critical to investigate the integrity and reliability of casing grades provided. Thus, numerical methods such as FE become invaluable as opposed to standard casing selection procedures.

This work models stability of casing in the wellbore using a commercial industry accepted FE package – Abaqus 6.12. The model was developed using simple plane stress and plane strain elements with corresponding boundary conditions. Various mechanical properties of steel casing, concrete, surrounding rock and interfaces were modeled to mimic a full scale industry scenario. The model investigated casings under HTHP, mechanical failure criteria in terms of elasticity, plasticity of material, geometric non-linearity and compared with other existing analytical models in literature in other to validate the model.

It was observed that the model becomes highly unstable under HTHP environment, hoop and radial strains in the wellbore casing increased as the temperature and pressure of the transported fluid in the wellbore increased. Areas of stress concentration in the casings can easily be observed in the model and it shows an efficient procedure for investigating the stability of casings in harsh conditions. Casings were subjected to HTHP to predict optimum configurations for different scenarios.
Finite Element Analysis of Induced Stresses on Injection Wells using Plane Stress and Strain Elements
Authors: Ikponmwosa U. B , Nwankwo E , Bello K. O , Olafuyi A. O
Published: July 2015

Casing failure has become a common occurrence especially in injection wells, which often affect development objectives of intended reservoirs. Stresses induced by injection of fluids (e.g. water, CO2, steam) in a well may affect the integrity of the casing, cement and surrounding formations. Thus, a simplified and reliable assessment of the thermal stresses induced in casings are necessary in predicting the integrity of well in complex and unconventional production activities.

The injected fluid cause fracturing of the formations and this induces local compression and tensile stresses in the various casing strings landed and cemented in the well. This work presents a quick and cost effective procedure for obtaining appropriate grades of casing using finite element (FE) method. The model is developed for quick assessment of well integrity using a well-known commercial FE package- ABAQUS 6.12-1. The ABAQUS’ plane stress and plane strain elements with associated material properties were used to model the thermal stresses in casing, cement and near well bore. The effect of varying the thickness of casing was investigated and an optimum thickness corresponding to various fluid conditions was obtained. The developed model was compared to existing models in other to assess the accuracy of the model. A parametric study was conducted on the effect of casing dimensions on the stresses and strains developed in the steel casing.

The results of the study showed that strains and stresses on the casing vary directly with increasing temperature and pressure of transported fluid in the wellbore casing. A strain based failure criteria was developed to aid the well design engineer in selecting appropriate casing thickness and diameter. The model presented shows a quick and reliable procedure for obtaining dimensions of casing subjected to unconventional environments.
Optimization of Hole Cleaning Using Dynamic Real-Time Cuttings Monitoring Tools
Authors: Dosunmu Adewale , Orun Cosmas , Anyanwu Chimaroke , Ekeinde Evelyn
Published: July 2015

Optimization of hole cleaning remains a vital challenge when planning and drilling deviated, high angle and extended reach wells. Hole cleaning depends on a number of factors and as to date most existing models have been deployed in solving hole cleaning problems. However, the flow rate predicted by these models may not be feasible to apply practically in field operations because it gives a pressure exceeding allowable limits of the pop-up valves on the mud pump. This is the major cause of downtime during drilling operations. This research is aimed at adding value to the existing models in achieving better hole cleaning and reduced down time. This was made possible through the use of cutting monitoring model which is a real time and quantitative tool. A case study on a well being drilled in the Niger Delta was conducted whose from which it was observed that within 5800ft to 11500ft, the hole was not properly clean as less cuttings were recovered. This information was used to initiate hole cleaning procedure. From the validation, the results shows Non-Productive Time associated with hole cleaning has a significant drop of 2-5 days when the cutting monitoring model is used in conjunction with the existing models.
Formulation of Demulsifiers from Locally Sourced Raw Materials for Treatment of a Typical Nigerian Crude Oil Emulsion
Authors: Sulaiman A. D. , Abdulsalam S. , Francis A. O.
Published: July 2015

Crude oil produced from the depths of the earth and during processing is associated with water or aqueous solutions of salts, particularly sodium chloride and during spills over waters, in the form of emulsions. Nigeria, an oil producing country, has remained dependent on foreign demulsifiers for the treatment of crude oil emulsion. This water interferes with refining operations, provoke corrosions, increase heat capacity and reduce the handling capacity of refining equipment and pipelines. Four samples of crude oil emulsion were collected from Ughelli East stations W/10L, W/10L, W/8L and W/1T, and labeled A, B, C, and D respectively. These samples were kept for few days at regulated temperature below their well head temperature to allow for natural gravitation. Meanwhile, four blends of local demulsifiers were formulated using locally sourced materials of non-edible jatropha curcas oil, industrial camphor, paraffin wax, starch from cassava and prepared liquid soap. These blends were used to treat the crude oil emulsion at a ratio of 1:50 ml using bottle test method at room temperature and regulated well head temperature in a water bath alongside the patent Separol N46 demulsifier as ‘control experiment’. The comparative results obtained showed that all local demulsifiers performance increased with separating time and operating temperature, while equal dosage of patent Separol N46 showed no performance. However, treatments AWHT4, BRT4, CWHT3 and DWHT4 all at well head temperature showed that most water was expelled after about 480 minutes. These results showed that the demulsifiers produced from these local content materials were cheaper, time effective and broke the selected crude oil within a shorter time frame than the foreign demulsifiers.
A Model to Determine the Effect of Pore Pressure and Fracture Gradient on Stuck Pipe Management
Authors: Boniface Oriji. A. , Marcus N. M.
Published: July 2015

Estimation of pore pressure and fracture gradient is very important in achieving a successful drilling operation. With proper estimation of pore pressure and fracture gradient, the drilling engineers can design accurate mud density that can-balance and stabilize the formation pressure without fracturing the formation. Proper estimation will minimize washouts, kicks, lost circulation and stuck pipe. This paper is on a Model developed using Visual Basic and Microsoft excel applications to compute the mud hydrostatic pressure, pore pressure, overburden gradient, fracture pressure and the overbalance pressure from a real field drilling data in order to predict the possible depths were stuck pipes could occur. The results from the analyses showed that at the depths where the pressure difference between the mud hydrostatic pressure and the formation pore pressure was greater than 500 psi, the pipe would most likely get stuck while a negative overbalance showed a kick. Also, from the analyses, between 8,100ft to 12,300ft depth, the pipe was freed from sticking and there was no kick because the hydrostatic presssure between these depths balanced accurately with the pore pressure.(overbalance less than 500psi). But from 12,300ft to 12,700ft, there was a kick because the formation pore pressure was quite higher than the hydrostatic pressure due to the abnormal pressure zone encountered. This situation could be managed by increasing the mud weight while maintaining a pressure overbalance less than 500 psi and mud hydrostaic pressure less than the fracture pressure at the same time. However, from 14,800ft and above, there was pipe sticking because the pressure overbalance was higher than 500 psi as a result of high mud weight. This model provides a platform for Well Engineers to detect the zones where kicks are likely to occur and the zones where the pipe could get stuck thereby effectively reducing losses resulting from down time caused by stuck pipes and fishing operations.
IPSM Plays Key Role in Maximising Oil Production and Minimising Gas Flare in the Re-opening of A Swamp Field in Niger Delta
Authors: Obakhena O. Femi , Nnanna Erasmus , Wakama Miebaka , Linus Nwoke
Published: July 2015

FEDA field is a medium-sized, step faulted anticline located in the coastal swamp area of the Niger Delta. The field is located about 70km south-west of Port Harcourt, Nigeria and has produced approximately 126MMstb of oil and 127Bscf of associated gas. The field has been developed with 9 wells (18 strings) with one well abandoned. Production from the wells is maintained by natural flow supported by a strong aquifer drive. The field was shut down for about 5years between 2008 and 2013 due to integrity issues with the trunk line. As at 2008 before the field was shut down, it produced 4.8Mbopd from 3 wells (5 strings). In 2010, a new trunk-line was commissioned which led to the re-opening of all the fields in the Swamp area including FEDA. However, there were various challenges that needed to be addressed before the flow station could be re-opened. One of such issues was the availability of gas to run the Low-Pressure, (LP) compressor, given its turn-down volume and due to restriction placed by the new flares-down policy being championed by SPDC.

In order to solve this problem, an Integration Production System Model (IPSM) was constructed. The model was calibrated ensuring accurate split between low pressure and high pressure gas streams which is not often considered in conventional IPSM analysis. The second issue was to consider the best scenario that would lead to optimum net oil production with the least volume of flared gas during compressor downtime in order to minimize production deferment.

The key outcome of the project is that accurate calibration of IPSM model can unlock asset deliverables and guide operations towards optimum oil production. This paper presents the results of an innovative use of the PETEX IPM to determine the accurate volume of low-pressure gas for re-start of an oil flow station in Niger Delta. The objective was to ensure that produced gas was not flared and that the volume of associated gas would be sufficient to operate the compression facility efficiently.
Deploying Continuous Improvement Methodologies to Improve Efficiency: A Way of Responding to Emerging Industry Challenges
Authors: Mustapha Adetoun , Umeh Nnaemeka , Adepoju Akeem
Published: July 2015

Local and global headwinds such as shrinking conventional oil reserves, environmental challenges, complex commercial frameworks; stricter regulations, higher production costs and drop in oil price continue to prevail in the oil and gas industry in recent times. In response to these challenges, the industry players (National and International E&P companies, Marginal Field Operators, Service Providers etc.) are constantly seeking ways to optimize operations and cash flow. This thus presents opportunities for the deployment of Continuous Improvement (CI) methodologies such as Lean, Six-Sigma as well as the recent development in the last few years that combines Lean and Six-Sigma to create “Lean Six Sigma”, to remove “wastes” (non-value adding activities) from processes and improve overall performance in business delivery.

While Lean focuses on removing non-value adding activity, aligning production with customer requirements and thus streamlining and optimizing process efficiency, Six-Sigma focuses on reducing process variation by delivering products at lower cost with improved quality and reduced cycle time. The application of the “Lean Six Sigma” is increasingly becoming a panacea for maintaining efficiency at all levels and driving operational efficiency in the industry. Continuous improvement not only makes good business sense but also improves job satisfaction.

This presentation will share what “wastes” look like in the oil and gas business, proffer ways we can spend less for more and share lessons learnt from deployment of continuous improvement in Shell Nigeria.
The Seamless Startup of the Ofon Phase 2 Project: A Demonstration of TOTAL's Strong Commitment to Eliminating Continuous Gas Flaring In Nigeria
Authors: Kue Yeghenee , Hyest Emmanuel , Darque Philippe , Sabally Lamin , Odemudia Abel
Published: July 2015

In the year 2000, TOTAL had announced that it would no longer continue routine flaring of associated gas on new oilfields development; and will make maximum efforts to stop continuous flaring on all existing installations. In 2004, TOTAL joined the Global Gas Flaring Reduction Partnership, A World Bank Initiative committed to reducing global gas flaring. The resolve of TOTAL's commitment to eliminating continuous gas flaring on all of its installations became overwhelming that between 1998 and 2005, TOTAL had reduced gas flaring by 40% despite, strong production growth within the same period.

In 2014, TOTAL set the objective to cut associated gas flaring by 50% from the 2005 baseline. Covered in this objective is the elimination of gas flaring on OML 102 - Ofon Oilfield, Nigeria; for which the Ofon Phase 2 Project have been endorsed and expected to achieve alongside other objectives. The project was scheduled to take off seven years after the phase 1 development which achieved its first oil in December, 1997 with no facilities for the utilization of the produced associated gas. Continuous gas flaring thus became unavoidable and thus served as the only way to safely dispose of the unwanted associated gas produced together with crude oil.

The eventual completion and realization of the seamless startup of Ofon phase 2 project, achieved in a context of high levels of local content coupled with the implementations additional energy efficient systems aimed at reducing global warming and energy consumption together is a clear demonstration of TOTAL's resolve to the sustainable development of the Niger Delta and the elimination of continuous gas flaring in Nigeria. In full compliance with Nigerian law, TOTAL has now eliminated gas flaring on OML102 – Ofon Oilfield. The elimination of gas flaring on the Ofon oilfield is also a significant milestone for TOTAL's environmental targets as it represents a 10% reduction in the Group's E&P flaring.

This paper presents the strategies and plans that were successfully implemented on the Ofon phase-2 project, which thus led to the realization of the seamless startup and consequently cascaded to the elimination of continuous gas flaring on the Ofon Oilfield Complex. The actions that were taken to drastically reduce the duration of the first oil startup which significantly reduced the initial startup flaring are also presented.
Case Study: Planning and Execution of a Subsea Hpht Well in the Niger-Delta
Authors: Nwagu Chike
Published: July 2015

Addax Petroleum Nigeria operates the OML-126 and 137 blocks in Nigeria. These are adjacent oil and gas blocks, located in the Niger-Delta region offshore. The close proximity of these blocks, and their similarity in terms of reservoir formation, means drilling activities in these blocks have had similar experiences. Past exploration wells targeting deep reservoirs in the blocks have experienced well control incidents resulting in the loss of millions of dollars due to the loss of several Bottom Hole Assemblies (BHAs), the loss of the wellbores and consequentially the premature termination of the projects. These well control issues were largely due to the pore pressure uncertainties in these blocks, which made it difficult to determine and plan the appropiate mud weights, required for the high pressures of the deep reservoirs.

The Star-6 (ST-6) well was a subsea High Pressure High Temperature (HPHT) exploration well, which was successfully drilled by Addax Petroleum Nigeria between September – October, 2014. The well is located in the OML-126 block.

Despite the short time frame for planning the well, with a range of possible pressures and temperatures, the drilling and exploration teams worked together to maintain safety and performance, and to overcome various logistical and operational challenges. The success of the well can largely be attributed to; the detailed well engineering planning, successful implementation of lessons learned from past exploration drilling activities in the area and utilization of industry recommended drilling practices.

This case study, takes a look at the different stages of well planning and actual execution of the ST-6 well that led to the drilling by Addax Petroleum Nigeria, of the first successful exploration well to date that met all its objectives in the OML-126 block.
Economics of Heat Loss Material Design in Transportation of Stranded Gases as Hydrates
Authors: Dosunmu Adewale , Udoh Nse-Obong , Ekeinde Evelyn , Anyanwu Chimaroke , Okoro Emeka
Published: July 2015

The Transportation of gas as hydrate with time is a function of the nature of the Hydrate carrying material of which when poorly designed can lead to loss of gas due to untimely re-gasification and hinders profit making. It is on this note that after the production of hydrate with natural gas, the ability for the Hydrate to reach its final point without on-transit re-gasification is seen as to be a function of the nature of the carrier material designed. In this study a robust software, HYGAS, has been developed to analyse the economics of the newly designed (heat loss) carrier model for transportation of natural gas by means of hydrate. Key parameters including the flow rate of the feed gas, abandonment rate and decline rate were considered. Also, the fiscal Parameters like the Gas price, Inflation rate, Royalty are considered. Finally, the CAPEX, OPEX, Depreciation and income tax rate are also taken into consideration during the designing. From the design, it is observed that at 0% discount, Internal rate of returns (IRR) or breakeven will be at nine years to come and at 15% discount rate, the IRR or Breakeven will be at seven years to come. The program at various discount values inputted can continue to give corresponding breakeven until a Most favorable condition can be met. Hence, Profit maximization can be attained.
Deployment of Remotely Operated Aerial Vehicles: Managing Asset Integrity in the 21st Century
Authors: Asiodu-Otughwor Isioma , Akhibi Osemhen , Aja-Onu Uchenna
Published: July 2015

Drones have found applications as toys, military equipment and parcel delivery services. Deploying Remotely Operated Aerial Vehicles (ROAV) has enabled new exciting frontiers to be broken in the upstream and downstream sectors of the industry. ROAVs are unmanned light-weight aircrafts that are remotely controlled and often kitted with instruments and cameras for diverse use-cases. Attaching a high definition camera converts the vehicles into data gathering systems that can work in remote, dangerous and hazardous environments.

As part of the Shell Group's technology replication initiative, the use of ROAV technology for Flare inspection is being adopted as part of SPDC's Asset Integrity Inspection procedure. The traditional inspection method, typically scheduled as a Turn-Around task, requires a shutdown of at least 3 days to allow for extinguishing of the flare, cooling down, and ascent of inspection personnel sometimes with rope access. Findings from the visual inspection of flare nozzles and stacks serve as input for maintenance and engineering work planning in future Turn-Around activities. A Non-Associated Gas (NAG) plant, a swing producer for a LNG facility, was selected as first deployment for this technology's application in SPDC.

This first deployment at the selected asset clearly demonstrates the following benefits; Elimination of working at height, Maintain safe distance from operating asset, Increased facility uptime and reduced deferment/interruption of operations. Other benefits include reduced cost to perform versus traditional methods (cranes, helicopters, scaffolding, and binoculars), shorter setup and faster inspection time, clear representation of asset condition using visible and thermal imagery and better planning of maintenance and turnarounds, especially in Life Extension programs. The application of this technology presents an innovative tool for asset integrity management with seamless data acquisition and storage which can be trended for condition monitoring application. It can be also used to inspect structures like masts, under-decks of offshore platforms, chimneys and tanks
Improved Data-driven Models for Forecasting Production Performance with Uncertainty Analysis
Authors: Ladipo O.. , Ogbe David O.
Published: July 2015

Data-driven analytical models are important tools employed in the petroleum industry to forecast production rates and reserves of petroleum assets. Studies have shown that existing rate-forecasting models project future performance trends by averaging the observed production history data with little or no preferential consideration of the influence of the trends of most recent historical production data. It is also understood that existing empirical data-driven rate forecast models do not account for the uncertainties involved in such future predictions.

In this work, new statistically-based data-driven models for production performance forecasting are developed. These models forecast future production performance trends using statistical-exponential smoothing of the historically-observed data, attributing more weights to the most recent historically-observed performance trends. Both linear-exponential and double-exponential smoothing algorithms were considered in the study. The uncertainty analysis of these predictions is evaluated using the history-fit errors derived from the observed data and fits to the history. The models’ accuracy depends on the segment of the observed historical data selected for the initial data fitting and the trends of most recent historical production data—the tail end of the observed data. The application of the proposed statistically-based data driven models was demonstrated on several data sets. The results obtained from the proposed data-driven models compare favourably with the base forecasts derived from existing models such as the Arps’ Decline Curve Analysis techniques. The major advantage of the proposed models over existing models is that predicted forecasts include a range of possible performance trends honouring the observed production history with the associated probabilities and confidence intervals. The major contribution of this work is that coherent statistically-based models have been developed for forecasting production rates and reserves of petroleum assets with uncertainty analysis.
Strategy For Setting Up A Successful Drilling Bits Performance Contract
Authors: Oikelomen S. B. , Ogunnoiki J. O. , Iloabachie T. U. , Oboarekpe B. A.
Published: July 2015

This paper defines the strategy for setting up a successful Drilling Bits Performance Contract in the oil & Gas industry. Contrary to the traditional and common type of drilling bits agreement that promises payment for bits usage irrespective of performance, this performance based contract instils the required motivation in the bit application engineer to actively participate in upfront well planning and use a risk based approach to provide the best bit that would deliver exceptional results.

The drill bit is comparatively a small cost item in the drilling assembly. An expensive 8-1/2” PDC bit might cost about US$50,000. However, when it fails, the cost of recovery might vary widely from US$0.3 – 3 million; considering a simple remedial action such as tripping out of hole for bit change to losing bit cones in hole, fishing, plug back and side-track operations. In the traditional form of drilling contract, the bit supplier gets paid for all bits supplied and used irrespective of the bit performance, while the operating company bears all the risk. The performance based contract supports a shared ownership of the drilling operation and the associated risks.

In setting up a performance based contract, it is customary for the bits contractor to provide a long list of exceptions on why the contract may not be workable. Suppliers would usually want to walk away from investigating root causes of bit failures and ascribed the causes of failures to external factors like drilling practices, directional drilling equipment, driller's experience, information on lithology, et cetera. This paper will provide information on how to resolve such exceptions and set up a workable performance based contract.
Optimizing Hydraulics For Drilling Operations
Authors: Ugochukwu Okoli
Published: July 2015

Hydraulic modelling is an integral part of drilling operations, thus its importance for the efficient delivery of a wellbore cannot be over emphasized. The standard API methods for drilling fluid hydraulics assume either Power law or Bingham Plastic, these models provide a simple way of estimating required parameters for efficient drilling operations, but for conventional wells. These models are sometimes not accurate when used to model the hydraulics of more difficult wells.

When drilling fluid is circulated, pressure drop takes place due to friction between the fluid and the surface of the stand-pipe, rotary hose, swivel, Kelly, drill-pipe, drill-collar, drill-bit, and the annulus between the drill-string and the open hole or casing. This generates a total frictional pressure drop in the hydraulic circuit called the Stand Pipe Pressure (SPP). The Equivalent Circulating density (ECD), which is generated from annular pressure losses, needs to be predicted correctly to ensure that the fracture gradient of the formation to be drilled is not exceeded, as there will be losses of the drilling fluid into the formation and potential wellbore instability problems.

The paper discusses seven (7) rheological correlations/equations from studies (Robertson-Stiff, Casson, Carreau, Sisko&Willamson, Hershel Buckley, Cross and Modified Bingham Plastic) which have been used in different conditions to simulate and predict the parameters required for efficient hole cleaning operations. It then highlights the magnitude of failure that occurs when simple hydraulic correlations/models are used for complex wells and very viscoplastic fluids.

The paper compares and discusses the variation with actual results when the Bingham Plastic, Power, Hershel Buckley and Robertson Stiff models are used to model fluid hydraulics. It proposes that the correct hydraulics of a particular well depends on the nature of the reservoir and bottomhole conditions, as the data from an offset well might not be representative of a target well. Thus it is required that an engineer should run different simulations using different hydraulic models and then compare with the actual data during operations. The difference between the simulated and actual can be used as the fudge factor to further optimize the hydraulics for other hole sections or wells with similar configurations, if the best fit hydraulic model is unavailable in the simulator.
Flared Gas To Sellable Products: Total Gas Consumption Technology Solution For Stranded Gas Fields In The Niger Delta
Authors: Fagbami Debo , Obofukoro Ejiri , Maduike Basil , Ekpeti Egoyibo
Published: July 2015

The negative impact of increased industrialization and urbanization has been a source of major concern to industrial stakeholders. More specifically, crude oil exploration and production has contributed largely to environmental degradation. Associated gas produced alongside crude oil production, which is being flared all over the Niger Delta has been a perennial source of environmental pollution. The attendant impact on the quality of life of the local population can also not be over emphasized. Flared gas emits carbon monoxide into the environment as well as warm up the environment, thereby contributing to the global warming scourge. It has been recorded that over 17 billion cubic meters of natural gas is flared annually around the Niger Delta region, a volume, which equates to about a quarter of the current power consumption of the African continent. There is an urgent need to devise techniques and methodologies to end gas flaring and preserve our environment. One such way is the conversion of associated gas to products of value. This paper examines the utilization of the gas to products/liquid technology to help combat an age-long problem while highlighting the socio-economic benefit of the solution. A practical case study of a total gas consumption technology solution is described with recommendations for future work and practice.
Power Distance Orientation and Employee Help Seeking: Trust in Supervisor as a Mediator
Authors: Ji Yang , Zhou Erhua , Li Caiyun , Yan Yanling
Published: July 2015

We explored the mechanism and effect of supervisors' power distance orientation in relation to employee help seeking by way of a hierarchical linear model based on a sample of 311 employees working in 12 Chinese firms. Results indicated that power distance orientation had a significantly
negative impact on employees' instrumental and emotional help seeking as well as their trust in the supervisor. Affect-based trust mediated the relationship between power distance orientation and instrumental and emotional help seeking. Further, cognition-based trust mediated the relationship
between power distance orientation and instrumental help seeking. Implications for theory and management are discussed.
Perceptions of Korean Students with Impaired Vision About Preparation for College in High School
Authors: Kim Kyeong-Hwa , Kim Joungmin
Published: July 2015

Our purpose in this study was to examine the extent to which students with a visual impairment perceived preparation for college in high school as being important, how well they felt they had been prepared for the transition to college in high school, and the level of their satisfaction
with these transition education support facilities and services. Analysis of survey responses from 34 students with impaired vision indicated that these students believed that the support and services they received at high school were important in easing their transition to college but that
these services/support left them unprepared for the transition to college. In addition, they felt dissatisfied with the transition education support and services provided before going to college.
Differences in Buying Behavior of Self-Lovers According to the Form of Self-Love
Authors: Hwang Jae Won , Kim Seo Young
Published: July 2015

We assessed whether or not individuals high in narcissism and those with high self-efficacy showed different behaviors in buying situations, by collecting quantitative responses to scenarios using an online questionnaire. The Study 1 participants comprised 133 students at universities
offering 4-year college courses and Study 2 participants were 83 workers and 15 university students. Results of Study 1 showed that narcissists depended more on visual information whereas people with high self-efficacy depended more on attribute information. In particular, covert, unlike overt,
narcissists depended on visual information in private buying situations. In contrast, people with high self-efficacy were found to depend on attribute information in public buying situations in which they could display their ability to others. In Study 2, behavioral differences were verified
between narcissists and people with high self-efficacy depending on display methods. Narcissists preferred brand displays, whereas people with high self-efficacy preferred product displays.
A Demonstration Model of a Mobile Expert System with Augmented Reality User Interface Supporting M-28 Aircraft Maintenace / Prototyp Przenośnego - Ekspertowego Systemu Z Rzeczywistoścą Rozszerzoną Do Obsługi Samolotu M-28
Authors: Golański Piotr , Perz-Osowska Małgorzata , Szczekala Marek
Published: July 2015

The paper discusses the problem of supporting aircraft diagnostic and maintenance processes. A possibility of usage of modern technologies, that could facilitate aircraft’s maintenance procedures and increase safety of their service, is presented. A usage of a mobile device, with implemented expert system and user interface based on augmented reality technology, is suggested. Proposed system structure is presented in the paper. Also, a possibility of usage of such a system is demonstrated on M-28 aircraft simulator