bluuebunny/crossref_metadata_2025 huggingface dataset:
Trolls and Its Augmentation in the Cyber World of Kerala
Authors: P V Sarada
Published: July 2016

                              Internet enthralled new generation cannot think of a world without social media. Social media itself became a platform for open ended discussions and enlightening sources of knowledge. Information revolution creates unbounded world where sumptuous trade, commerce, communication etc take place. The effect of cyber world is far reaching which surmount all other media that facilitates the growth of cyber media. The utility of cyber world is multifaceted.ie it includes entertainment, informative, educative, purposive, etc. Many aspects of internet had far reaching results. Among them trolls are significant in opening the eyes of the audience to the various social, political, gender, lingual and cultural issues. Pointed condemnation, naysayer, satire are the general nature of trolls. Sometimes it focuses on heartless defamation on individuals in power and positions. Ideas that are spread virally through internet may turn out to be reasons for social transformations. It can correct corrupted individuals, modify negative attitude of society towards the underprivileged by poignant criticism through internet trolls.  Its interference in social, cultural, political practices is noteworthy to mould a new perspective in society.

                                    Here the endeavor is to find out the concept of trolls and its importance in the cyber world of Kerala. The trolls provide a public space for open criticism and satire. Sometimes it may attack individuals without mercy but generally they are having a wider range of usage. It became instruments of social change when it is used rather in constructive brighter aspects. Sometimes it is used to dismantle the sacred images and idols which are actually beyond the reach of criticism in reality. But the anonymous aspect of virtual world actually opens up a possibility of razor-sharp ridicule and mocking.
Personal development planning and ePortfolios in Speech Pathology:Student and staff perceptions
Authors: Strampel Katrina , Lewis Abigail
Published: July 2016

This paper describes the evaluation of the use of an ePortfolio which was embedded across a speech pathology program and designed to enhance employability. Personal development planning (PDP) is a key part of employability and includes learning, reflection, goal setting and understanding the wider context. Students’ perceptions of their engagement in this process were evaluated using a mixed methods approach. Qualitative data was collected through student focus groups and individual staff interviews, while quantitative data was collected via a student questionnaire (reported in Lewis & Strampel, 2014). Qualitative data was analysed using NVivo following the six phases of thematic analysis described by Braun and Clarke (2006). This paper reports the themes which emerged from the focus group data. A key finding of the study was that the platform used was not ideal for the ePortfolio purpose causing frustration and negative reactions from students and colouring their engagement with, and enthusiasm for, the ePortfolio activities. Students achieved some of the objectives of personal development planning, especially goal-setting, but it was not until students were in their final year that they saw the links with their future career and employment. Further embedding of key tasks would enhance employability aspects, including for example involving industry from the first year and modelling the PDP process with students.
Understanding the Potential of ICTB Facies in DW Gulf of Guinea
Authors: Itua Osazua J.
Published: July 2016

Though substantial hydrocarbon resource volumes are believed to be located within Inter Channel Thin Bed (ICTB) facies in deep-water (DW) reservoirs in the gulf of Guinea, there seems to be no dedicated effort to harness them. This is partly due to the challenges associated with how to identify, accurately characterise and ascertain producibility from ICTBs. In this paper, a workflow to identify and characterise ICTB is presented along with a review of literature that demonstrates ICTBs can be prolific producers.
Virtual Pipeline Technology in Nigeria: Technical and Economic Analysis
Authors: Princewill Ikpeka , Ikiensikimama Sunday
Published: July 2016

Plagued by issues of insecurity, unstable demand, high initial development cost, bureaucratic bottlenecks and challenging terrains, the construction of new Gas transmission Pipelines has suffered a lot of setbacks leading to stalling of projects and in some cases abandonment by stakeholders. Based on the above premise, a study on Virtual Pipeline technology was carried simulating the fiscal and operating system in Nigeria. This study explores the use of a new technology for Gas transportation from source points to demand points especially where distance and demand do not justify an investment in a gas pipeline. Virtual Pipeline is a system that allows for natural gas transportation in the form of compressed/liquefied gas using modules coupled to mobile platforms, which are transported by trucks, ferry boats, boats and/or rail platforms. In order to find the most economically viable means of exploiting a stranded gas reservoir and with a vision to eliminate Gas flaring, an excel-based economic model was built and used to Compare Pipeline transportation against Virtual pipeline transport. Also included in this study, is a step by step review of all processes that make up the virtual pipeline technology. Results from the economic analysis showed that for transporting gas to demand points less than 20miles, CNG proved to be better than conventional pipeline transportation. Factors affecting the profitability of a gas transportation project were also identified in the model. A sensitivity analysis was carried out using @Risk™ Software, in order to quantify the effect of these variables on the choice of the optimum Gas transportation type.
Zonal Production Prediction in a Two Layered Intelligent Well System Using Downhole Real Time Data
Authors: Kudayisi Ayopo
Published: July 2016

One major requirement of many governments for allowing production commingling is the ability to allocate production to individual reservoirs that the well produces from. Despite the continuous stream of data that is generated from the downhole gauges in an intelligent well system, operators may still find production allocation difficult.

This work proposes a technique for real-time production prediction for individual reservoir with data from pressure and temperature gauges using developed software - KomptWell. The software models the well completions, fluid characteristics and predicts individual zonal rate at different ICV positions.

The software uses the modified Sachdeva choke model to predict the mass rates from the downhole control valves of each of the well. The equations are complicated and are required to be solved numerically. Firstly, it determines if the flow across the downhole valves is critical or subcritical and secondly it determines the rates across each valve.

The working of the software is demonstrated by a hypothetical two-zone intelligent well completions system with multi-phase production. A comparison is made between this methodology and the one that uses the gauge values directly without correcting for pressure difference. It is observed that significant difference exists between the software method and the latter..
Model for Quick Permeability Determination of Niger Delta Sands Using Grain Size Analysis
Authors: Bamisebi Adetiloye J.
Published: July 2016

It generally has been recognized by previous investigators that grain size is a fundamental independent variable controlling permeability in unconsolidated sediments. Several models that have been developed for estimating permeability based on grain size. However, these equations are based on empirical studies, and the results are not necessarily transferable from one location to another. It is therefore important to determine which permeability equations are appropriate for use in the Niger delta basin. The author seeks to establish the use of grain size data from Sieve analysis to determine the permeability of sediments from the Niger Delta area. Sieve analysis experiment was performed on samples from different wells and depths and the grain size data retrieved. Permeability was also determined using routine core analysis methods. Regression analysis tool on Excel was used to derive an empirical relationship to predict permeability from grain size data. Two models were developed and they represented different permeability regimes (k< 1000 md, k≥1000 md). The accuracy of this method was checked by correlation with standard routine core analysis permeability data. Statistical indices showed percentage error (-0.0627%, 0.0008%) and correlation coefficient (r = 0.9844, 0.631). Sensitivity carried out on the model variables showed that the grain diameter and the sorting are the key variables controlling the determination of permeability from these models.
Success Story of Nigerian Content Development Implementation in SPDC Drilling Operations
Authors: Awe S. O. , Eze N. , Akhideno M. , Iyamu I. , Weli I.
Published: July 2016

The drive of Nigerian government to boost economic activities through local capacity utilisation, human capital development and empowerment of indigenous companies resulted in the implementation of Nigerian content development in the oil and gas industry which was previously exclusive to the multinationals. The Nigeria Oil and Gas Industry Content Development Act of 2010 provides the legal framework to facilitate and promote mandatory participation of companies owned by Nigerians in the high-risk and high-cost petroleum industry. Prior to the enactment of the act, insignificant number of Nigerian companies had the financial strength and technical know-how required to be competitive in the petroleum sector compared with the well established multinational operating and service companies. These factors made compliance with the requirements of the act a daunting challenge for the sector.

Historically, The Shell Petroleum Development Company (SPDC) has played important roles in the development of various aspect of petroleum industry in Nigeria owing to its visionary leadership position in the sector. The SPDC began the Nigeria dontent Development (NCD) implementation in various aspects of its business right from the time the idea was first muted in 2001. This disposition of the company to NCD ensured that by the time the act was enacted in 2010, competent local contractors in drilling operations, production maintenance, facilities construction and so on had been developed. The transition of the SPDC from the implicit period of NCD implementation to the period when compliance to the provisions of the law became mandatory was smoothened by the development of the local contractors ahead of time.

The approach taken by the SPDC contributed to the realisation of major success stories in various arms of its operations. One of such achievements is the degree of compliance of the drilling operations department with NOGICD Act requirements. This paper details various schemes that were employed by the drilling and contracting departments in conjunction with the National Petroleum Investment Management Services (NAPIMS) and the Nigeria Content Development and Monitoring Board (NCDMB) towards the realisation of the nation's aspiration of domesticating technology, human capital development, financial empowerment and economic development, and then leveraging the resources available in the oil and gas industry.
Study of Fines Mobilization by Flow Rate in the Presence of Aluminium Oxide Nanoparticles
Authors: Ogolo Naomi A. , Ezenworo Ebuka J. , Ogri Emeka , Wali Samuel M. , Nnanna Echi C. , Onyekonwu Mike O.
Published: July 2016

One major factor that triggers fines migration in formations during hydrocarbon production especially in the presence of water is high flow rates. Low flow rates have been recommended to prevent fines mobilization but this solution is not always practical because there is a critical rate below which production becomes uneconomical. It is the objective of this work to find out if the presence of Aluminium oxide (Al2O3) nanoparticles in sand can allow for a relatively high flow rate without mobilization of the clayey fines. The experiments were conducted under different flow rates ranging from 3 – 9ml/min. while flowing brine of 30g/l salinity through the sand until breakthrough of fines occurred. In the first phase of the experiments, the clayey fines were contained in the sand samples while in the second phase, the fines were contained in the injected fluid flowing through the sand.

Experimental results showed that relatively large volumes of fines free brine can flow through sands containing Al2O3 nanoparticles at relatively higher flow rates without fines mobilization which is in contrast to the reference experiments. At a flow rate of 9ml/min. for the first phase of experiments in the presence of medium crude, fines breakthrough occurred at 1pore volume for the reference experiment while fines breakthrough occurred in the samples containing Al2O3 nanoparticles after flowing more than 12pore volumes of brine through the sand. For the second set of experiments, fines breakthrough occurred at 1pore volumes for the reference case while it occurred in the samples containing Al2O3 nanoparticles after flowing about 6pore volumes of brine at a flow rate of 5ml/min. in the presence of medium crude. This implies that at certain increased flow rates, large volumes of brine can be produced from sands containing Al2O3 nanoparticles before clayey fines are mobilized compared to when Al2O3 nanoparticles are absent in the sand. This indicates that Al2O3 nanoparticles have the capacity to delay fines migration in sand at relatively high flow rates.
Successes and Challenges in Delivering Deviated Gas Wells
Authors: Festus Ijeoma , Okongwu Obinna , Mfonnom Goodluck , Okonkwo Chukwudi , Okogbe Bolaji , Orimoloye Samuel
Published: July 2016

The prospects for gas development for domestic use and export which is driven by the national gas policy and incentives, has sprang up a lot of gas development projects in Nigeria such gas power generation plants, liquefied natural gas plants, gas-to-liquids projects, associated gas gathering projects etc. With these projects, the Nigerian government intent is to raise income from Nigeria's huge natural gas resources, raise gas utilization, achieve zero gas flare and create permanent employment for thousands of Nigerians. This in turn has created huge deficit between local gas production and the demand.

Seplat Petroleum Development Company in her JV operation in OML 4, 38 and 41 has cumulative gas reserves of approximately 1820 Bscf with two gas processing plants, the Oben gas plant and Sapele gas plant. Seplat cumulative gas production as at 2014 was at 147mmscf while the company's base domestic demand stands at 300 mmscf. Owing to this deficit and the prospective growth in demand due to increasing gas infrastructures for power and the manufacturing sector, Seplat embarked on gas drilling campaign from 2014. Since inception of the Seplat in 2009 to date, a total of sixty one wells has been drilled and out of which, twelve were gas wells (six new wells and six workover wells). The six new gas wells which consist of Oben 43, Oben 44, Oben 45, Oben 46, Orogho 7 and Okporhuru 8 were all deviated wells as shown in Figure 3. Approximately fifty percent of the proposed 2016 drilling work program are new drill gas wells and the percentage is expected to increase in the coming years.

This paper focuses on the challenges and successes which were recorded during the planning and execution of the deviated gas wells.

Surface location selection and well trajectory optimization to meet the geological objectives. This was achieved by deviating the wells between 45°to 75°inclination to increase the production zone interface in thin reservoirs. Optimum completion tubing size and wellhead selection. This was achieved by modifying the 13 5/8" x 9 5/8" tubinghead spool to 13 5/8" x 10 ¾" tubinghead spool without compromising the wellhead integrity in order to deploy a swaged 9 5/8" x 10 ¾" production casing string and the completion tubing string. Achieving effective zonal isolation on the production casing primary cement job across the gas bearing sands. This was accomplished by adopting two non conventional techniques vis a vis deployment of 10 ¾" x 9 5/8" combination wiper plugs and cost effective preflush "Gustacho Pill" to remove gelled mud, allowing a better cement bond with casing and formation. Effective sand exclusion. Utilized 8 ½" x 10 ½" bi-centre bits to underream the reservoir sections to 10 ½" for higher annular clearance required to install premium screens for external gravel pack and maximize production.
Fast-Tracking Field Development in a Green Field by Eliminating the Need for Appraisal Using Multidisciplinary Evaluation Methods
Authors: Kakayor Omagbemi George , Oragui Ijeoma , Esho Muyiwa , Anyaehie James
Published: July 2016

Field development is heavily contingent on the proper delineation of the field's resource volume along with the subsurface uncertainties. For green fields, appraisal drilling reduces uncertainties, but has the potential of cost escalation and delays in project timelines thus making projects less competitive. This study highlights how a fast tracked appraisal/development strategy for 1.7 Tcf of gas development project worth $800mln was developed and approved by the regulatory authorities.

The GATOE field under review is in the South East of the Niger delta, Nigeria. The field is 80 km2 in aerial extent. It consists of 11 stacked hydrocarbon-bearing reservoirs of varying thicknesses and, is penetrated by 5 wells. Seven (7) of these reservoirs (3 AG and 4 NAG) with GIIP of 900 Bscf that are ‘ready-to-go’ gas resource were captured in the ‘Tranche-1’ development scope. The remaining 4 reservoirs which are AG reservoirs with uncertainties in the actual oil column were grouped for trench-2 development but will be appraised during the Tranche-1 execution phase.

Usually regulatory approval for field development is secured post appraisal drilling. This study however, proposes a concurrent field development and appraisal scheme where development wells (for fairly known reservoirs) are used to also appraise reservoirs with appraisal needs. Thus significantly reducing the number of appraisal wells (from 3 to 1) and ensuring the delivery of fast-tracked field development (early ‘First-gas’ date). The only appraisal well will be drilled at the tranche-1 execution stage. In order to achieve this, a multidisciplinary evaluation of all available data was done in addition to the use of reliable technology. This is with the aim of demonstrating that the fast-tracked gas development will not jeopardise the recovery of any potential oil that may be proved from the appraisal exercise.

This study demonstrates the viability of a field development strategy in which ‘freezing’ of a development concept prior to full field appraisal can be achieved. The outcome is a massive reduction in appraisal costs and accelerated field development.
Guiding Seismic Interpretation Using Predictive Structural Models: Transfer Accommodation Faults in Onshore Niger Delta Reservoirs
Authors: Manuel Tekena , Glukstad Miguel Mora , Amrasa Kefe , Esho Muyiwa
Published: July 2016

There is general awareness of the importance of transfer accommodation faults towards controlling sediment dispersal, migration and hydrocarbon trapping in the deep-water thrust belt of Niger delta., These types of faults, although less understood, are also active in the onshore extensional part of the basin, where they can also exert important controls in sediment transport and/or reservoir geometry. These faults act as transfer mechanisms between major growth faults and provide a mechanical way to "accommodate" the non-orthogonal gravitational deformation. Although seismically we often map one single fault plane, these faults are more complex and could have a series of strands, which are often below seismic resolution.

The strands from transfer faults could also control deposition as they act as barriers that hold back sedimentation helping to delineate the depocentre on the hanging wall (HW) of the main normal fault. A gas well targeting an accumulation on the footwall (FW) of a major growth fault, missed its target by 149 ft. Using innovative "in house" processing technology, 3D PSDM data showed that the new well was drilled between two small crestal collapse E-W normal faults, which are limited to the east by a strand of a major NNE-SSW transfer fault.

This paper highlights the results of the new seismic interpretation, which looked at the geometry of the transfer fault in more detail and concluded that the interaction between the crestal collapse faults and the strands of the transfer system were important in the structural configuration of the target reservoir.

This type of approach is useful in areas of fault-fault intersection or poor quality seismic data where the presence of smaller scale accommodation faults can significantly affect depth prognosis during well planning and static volume computation.
Application of Web-GIS Technologies to Globally Manage Petroleum Asset Information
Authors: Amouroux Jean-Michel , Aneke Harold , Leclerc Jean-Charles
Published: July 2016

The ability to access and share valid and up-to-date technical information is a key element of our operational efficiency with the follow-up of our projects and operations. This will have a critical impact in case of incidents and/or crisis situations, as this could happen in sensitive area like Nigeria.

In case of a major crisis, we must be able to restore access to the identified critical facilities stored in GIS datasets within a time limit of 4 to 8 hours!
A New Approach in Rock Strength Constraining Using Petrophysical Logs for Effective Real-Time Wellbore Stability Management in Normal Stress Regimes
Authors: Bassey Akong , Usim Mike , Otutu Friday , Dosunmu Adewale
Published: July 2016

The geomechanical knowledge of rocks physical and mechanical properties could reduce the NPT incurred while drilling and production of a reservoir to a large extent by selection of proper/optimum operating envelope. Hence, a field development plan for each oil/gas field may contain optimized geomechanical procedures that take into accounts the rock mechanical principles and failure scenarios. "The unconfined compressive strength (UCS) and internal frictional interplays of rocks is the important rock mechanical parameters that plays crucial role when drilling an oil or gas wells". "(UCS) is the stress level at which rock is broken when it is under a uniaxial stress state (Bruce et al 2004)"; it can be used for real – time wellbore stability evaluation, bit selection management, and design of enhanced geomechanical earth models and cap integrity evaluation. Rock strength can be estimated along drilled wellbore using different approaches, including laboratory tests, core – log relationships and rate of penetration models. The benefit of a petrophysical log- derived method is that, it provides continuous strength profiles with depth. This is useful in delineating differences between near uniform zones, and identifying weaker zones. There is also a cost advantage in obtaining these data without having to perform extensive laboratory testing throughout the core interval.

"In this study, new equations for estimation of rock strength in Niger Delta formations are formulated based on empirically derived models that accommodate petrophysical log information such as the degree of shaliness detected over the entire logged interval, corresponding to shale and sand units (Fjaer, et al. 1990), lithology index etc., hence they are utilized for estimation of the rock strength profile for easy and effective geomechanical evaluations" (Dosunmu 2007).

A geomechanical enhanced framework coupled with discrete finite element analysis is utilized for prediction of UCS in any predefined well trajectory and batch depth analysis on the course of this research (study). Cross/post – validation shows that, the results from the formation discretization were compatible with realities (based on MEM utilization). This approach has proven to be useful for estimation of rock strengths and frictional interplays in any design well trajectory prior to drilling (predrill scenarios). Above all, it helps to determine the minimum and optimum mudweights required for real – time wellbore stability management during drilling, POOH, casing running and cementing, helps in preventing unplanned events leading to outrageous NPT's (Otutu 2013)
Role of Fault Transmissibility Analysis in Achieving Adequate Simulation History Match for a Light Oil Reservoir
Authors: Olu Okpani , Anil Ambastha
Published: July 2016

Reservoir simulation history match was recently carried out for the A7 reservoir located in the Niger Delta. The A7 reservoir is divided into two compartments ("Main" and "West") by a fault ("Center Fault") such that at initial conditions, the compartments have common Original Oil Water Contact (OOWC), but different Original Gas Oil Contact (OGOC). The difference between the OGOC of the two fault block is 24ftss. One well ("Well-A7") has produced from the reservoir in the West compartment. Well-A7 has been on production for nine years with three distinct produced GOR periods: Low-GOR, Mid-GOR and High-GOR periods.

Initial attempt to history match the performance of Well-A7 by assuming that the Center Fault was completely sealing resulted in the inability to match the Mid-GOR and High-GOR production periods. Consequently, the sealing potential of the Center Fault was further analyzed in detail. Examination of the Center Fault shows that the Main and West compartments have sand-to-sand juxtaposition in part of the gas zone; with the pressure difference between the gas zones of the two compartments at initial condition estimated at about 8 psi. This implies that the threshold pressure of the Center Fault was greater than 8 psi. Thus, it was presumed that the Center Fault was sealing at initial condition, but became non-sealing at dynamic condition when the pressure difference between the two compartments exceeded the capillary threshold pressure of the Center Fault.

Results/Conclusion

The GOR, water cut, shut-in-bottom-hole-pressure and flowing-well-pressure were history matched for Well-A7. Several history-match parameters were identified prior to history matching, but the parameters that had the most significant impact on history matching were the transmissibility and threshold pressure of the Center Fault. Good quality history-match was obtained with a fault threshold pressure of 25 psi. Some forecast results using this history-matched model are also presented.
HPHT Well Integrity and Cement Failure
Authors: Wilcox Bomá , Oyeneyin Babs , Islam Sheikh
Published: July 2016

A petroleum wellbore must have complete zonal isolation to maintain its integrity. This is primarily achieved by the cement sheath barrier that sits between the casing and rock formation. However, effective zonal isolation can be adversely affected by conditions such as high pressures, high temperatures, and high hole angles. These conditions are increasingly popular in deep-water drilling and can compromise the strength and integrity of the cement sheath if not anticipated early.

This paper presents some critical issues and factors that affect well integrity in HPHT wellbores. It also presents an analytical model of the interaction between the casing, cement sheath, and rock formation. This model also contains mathematical relationships for the interfacial pressures at the casing-cement and cement-rock contacts/interfaces. The study was limited to vertical wells as this allowed us, for purposes of symmetry, to analyse the casing-cement-formation relationship as a composite cylinder. The area of the wellbore that was analysed is the pay-zone area where the relationship between the casing, cement and rock formation is represented by a concentric composite cylinder. This paper is part of an on-going research project on well integrity at Robert Gordon University, United Kingdom.
Energy Security, Affordability and Availability: Implications on Economic and Industrial Growth in Nigeria
Authors: Igbokoyi Alpheus O. , Iledare Wumi
Published: July 2016

Energy is fundamental to the national economic and industrial growth. Therefore, access to affordable and sustainable energy is essential to the functioning of a national economy. In most developed nations, energy policy tends to focus on energy security, environment, economy and affordability of energy. No nation can grow beyond its energy development and management pedigree. While energy development as a source of income through exportation of hydrocarbons brings monetary wealth, energy consumption in the local economy is a good indicator of the socio-economic wellbeing and industrial growth of a nation. In other words, the prosperity of all sectors of a nation economy is tied to the prosperity and effective management of the energy sector. Nigeria continues to produce bulk of its energy resources for export over the decades. Unfortunately, the domestic economy continues to suffer a significant setback because of inadequate energy to energize the productive sector of the local economy. This paper examines energy consumption per capita and the economic data in Nigeria, and compare with the data from the United State of America as a developed economy, and China as a growing and emerging economy. Based on the comparison, we then forecast how much liquids petroleum will be needed to support the socio-economic life, industrial growth and the transportation in the country. Different scenarios are run based on the rate of liquids petroleum consumption in China and Africa. Our analysis shows that Nigeria might become an importer of crude oil between 2030 and 2035 as the country economy, industrial activities and population grow.
Optimizing Whipstock Sidetrack Operations
Authors: Ugochukwu Okoli , Okubor Eleanor , Aigbedion Prince , Ayodele Adetokunbo
Published: July 2016

The recent decline in the price of crude oil has necessitated more cost effective ways to sustain and increase production worldwide. From July 2014 to May 2015, Addax Petroleum Development Nigeria Limited (APDNL) embarked on a successful re-entry campaign in its shallow and deep water fields.

These wells' Vertical Lift Performance (VLP) had been compromised by excessive sand production; rather than drilling new wells to recover the trapped reserves that would otherwise not have been produced by the impaired wells, it was more optimal to re-enter the existing wells, recover their completions accessories and then side track into optimal locations within the reservoirs of interest.

These suboptimal wells were not considered for recompletion because in addition to excessive sand production, increased water cut and Gas Oil Ratio (GOR) meant that the drains were no longer in the best positions within the reservoirs to produce the trapped oil estimated to be left in the reservoir. The new side track wells would have their drains placed higher in the reservoir (based on production data from the soon-to-be-abandoned wells), but would not bear the full costs of drilling new wells nor their associated future abandonment liabilities.

Seven wells were re-entered during this period and side-tracked in cased hole with the use of hydraulic whipstocks, none of the side tracking operations witnessed significant down time. The whipstock was deployed to its intended setting depth, casing window milled and additional rat hole drilled in one trip.

Each phase in the whipstock operation had inherent risks and challenges that were successfully managed by identifying these risks early in the planning phase and mitigation steps put in place to ensure the operations were carried out with minimum Non Productive Time (NPT) as the cost implication of an operational mishap would have been severe.

This paper reviews the re-entry operations performed, challenges encountered with deploying hydraulic whipstocks. It also identifies the Key Performance Indicators (KPI) used to benchmark and compare the operational performance. Finally, this paper highlights the lessons learned during the re-entry campaigns and measures put in place to optimize future operations with respect to deploying whipstocks.
Cost Reduction Initiatives in a Low Oil Price Regime and Beyond: SEPLAT's Experience
Authors: Iyua Donald , Okongwu Obinna , Vaughan Bolutife , Orimoloye Samuel
Published: July 2016

Since the global crude oil price slump began in June 2014 ($125.86 per barrel: last known price peak before slump), companies in the oil and gas business have witnessed a sharp decline in revenues and eroded profits. Many international oil companies have declared huge losses running into billions of Dollars for 2015. There are efforts at reducing operating costs with attendant job cuts and freezing of non-essential projects. Global investments in projects in oil and gas have declined to levels seen only in the 1980s. With oil prices hovering at $40 per bbl, many projects become unviable except a lot is done to lower the unit development costs. This is more so for brown field developments where the reservoirs are matured. This paper will present the efforts made at SEPLAT to lower operating cost especially through reduced well delivery costs. The paper will mention some ideas explored in other areas such as contracting & procurement and business processes.

Seplat Petroleum Development Company PLC, an independent operator in Nigeria's upstream business has put in place sustainable measures that has helped to ensure she remains profitable while the low oil price regime lasts and beyond. The Drilling and Completion department which accounts for over 55% of the annual expenditure was at the forefront of this endeavour. Engagements were held with all contractors mainly aimed at mutually agreed reductions in contract rates. Discounts were obtained ranging from 5 – 30 % across various vendors and services. A review of well delivery processes, long lead items and logistics, appropriate technology and improved planning has led to some improvements. The competitive re-tendering of most services and the maturation of cost saving technologies will further improve wells project delivery cost and time, going forward. Company wide cost reduction initiatives and business process improvements will ensure the long term profitability of the company.
Revisiting the Assumption of Local Thermal Equilibrium in Thermal Floods
Authors: Lawal Kazeem A.
Published: July 2016

Notwithstanding their complexity, a good understanding of the heat-transport mechanisms and the associated temperature distributions is a critical success factor for the design and management of thermal projects exploiting underground oil resources. However, for mathematical convenience, it is often assumed that the reservoir exists in a state of local thermal equilibrium (LTE), which implies that the trio of injected heating fluid, in-situ fluid and the rock matrix in a particular location always exist at the same temperature. In essence, current treatments assume that the in-situ fluid and rock matrix reach the temperature of the injected fluid immediately they are contacted by the latter, tacitly neglecting possible time lag to accomplish heat exchange among these three elements.

Applying the principles of energy conservation at a pore scale to each element of the trio, this paper develops and solves a one-dimensional heat-transport model to investigate the validity of this fundamental assumption in thermal floods. The approximate analytic solutions under isothermal boundary conditions are presented in both Laplace and time domains. Employing the resulting solutions and a set of realistic input data, the conditions and time scales of validity of the LTE assumption are probed for steam, which is a popular and efficient heating fluid for oil reservoirs.

Results of the sensitivity studies suggest that the assumption of LTE remains credible for most realistic thermal floods. These findings notwithstanding, some conditions that threaten the validity of this fundamental assumption are highlighted.
Some Lessons from Gas Condensate Reservoir Development Evaluation Using Experimental Design
Authors: Shittu Hammed , Enekhai Henry , Ambastha Anil
Published: July 2016

Experimental design method is very useful in green field development. It helps to understand the impact of uncertainties on ultimate recovery, and hence, gives guidance on business decision making. Outputs from the process (Pareto/Tornado charts, selected models) are good exhibits for use in the uncertainty management plan, which also drives data acquisition and work plans for future stages/phases of the project.

This work shares some lessons from using experimental design for development planning of two Non-Associated Gas (NAG) condensate reservoirs. It demonstrates the importance of selecting appropriate design for proxy generation/Monte Carlo simulation runs – and eventual model selection.

This paper has two case studies: (i) a gas condensate Reservoir "A," with total of 20 parameters (9 discrete and 11 continuous variables), and (ii) another gas condensate Reservoir "B", which has 22 parameters.

Folded Plackett-Burman (FPB) design was first used in both cases. However, owing to limited number of runs, only linear proxies could be created. This did not meet the objective of the process, because it does not allow for generating interaction terms among parameters. The FPB runs were therefore used only as screening studies, while 3-level D-Optimal designs were subsequently used for response surface model (proxy) generation.

Four sensitivities were done on Reservoir "A": (i) 20 parameters with 300 D-Optimal runs; (ii) 14 parameters with 300 D-Optimal runs (after screening out less impacting parameters on objective functions); (iii) 20 parameters with 500 D-Optimal runs; and (iv) sensitivity (i), but with additional fresh 200 D-Optimal runs. The two sensitivities done on Reservoir "B" are: (i) 22 parameters with 200 runs; and (ii) 15 parameters with 300 runs. It was observed that only sensitivities (ii) and (iii) for Reservoir "A", and sensitivity (ii) for Reservoir "B" yielded meaningful proxies.

In conclusion, using Folded Plackett-Burman (FPB) designs alone in cases with many variables, as shown in this work, may not lead to meaningful proxies (especially, when there are interactions among parameters) because it is restricted to only linear proxies. Also, it is important to have adequate number of 3-level design (D-Optimal) runs for both process efficiency and proxy generation. Too few runs result in unreliable proxies, whereas too many runs take more time/computing resources. In addition, carrying large number of variables into the 3-level design stage requires more runs and also leads to more cumbersome proxies.
Gas Field Development Planning: Issues and Practical Solutions
Authors: Ambastha Anil K.
Published: July 2016

Nigeria has vast amount of gas and gas-condensate resources that have not been developed because of country’s traditional focus on oil reservoirs in the past. However, country is now embarking on a systematic development of gas resources. Objective of this study is to discuss issues being faced by all parties to evaluate gas resources and practical solutions to move forward with gas development on a large scale.

This paper discusses commercial (including team dynamics), technical, data analysis, and organizational capability issues relevant to development planning for gas fields. Practical solutions such as open and full communication among all stakeholders, due diligence to locate and analyze technical data, and proper bench-marking and testing of relevant recovery mechanisms in commercial software packages are proposed that would lead to proper evaluation of gas resources. It is emphasized that work alignment to resolve uncertainties and reach appropriate decisions is absolutely critical for project success. While practical solutions presented in this paper are especially geared toward gas field development, many of these thoughts and concepts are applicable for technical analysis of all petroleum engineering projects.
Alkaline-Surfactant Flooding in Niger-Delta: An Experimental Approach
Authors: Onyekonwu M. , Akaranta O.
Published: July 2016

Oil and gas production in Nigeria, recently advanced into secondary method of recovery of hydrocarbon aiming at tertiary recovery methods known as Enhanced Oil Recovery. It is of great importance to start the preparation for this phase now. Alkaline-Surfactant flooding is a tertiary recovery method used to produce extra oil from mature fields where oil is trapped due to capillary forces. These alkali are added to mostly reactive crude; they react with the naphthenic acid in the crude oil which forms a crude soap through the process of saponification, but most times, this crude soap are not sufficient, so surfactant are further injected to optimize its concentration in order to effectively reduce the interfacial tension between oil and formation water. Three conventional alkalis (NaOH, Na2CO3 and KOH) and two synthetic surfactant (Xero Detergent and Sodium Dodecyl Sulphate) were used as Enhanced Oil Recovery agent for a sand pack flood test in the laboratory. The comparative result showed that the Na2CO3 at 1%w/v concentration was better, though the KOH at 2%w/v concentration gave the best result marginally. It was also observed that the XD at 0.1%w/v concentration gave a result that can be compared to that of 1%v/v concentration SDS. Which shows that XD can be used as a substitute for SDS with low cost and availability been added advantage. Additional oil recovery after waterflooding for NaOH, Na2CO3, KOH, XD and SDS are 13.3%, 18.2%, 17.5%, 11.5% and 15.2% respectively.
Getting the Most of Niger Delta Fields; Countering the Effect of Urbanisation: SPDC Case Study
Authors: Sukubo Ibianga , Nwabueze Vincent , Okoro Chidi , Dennar Linda
Published: July 2016

Urbanisation effects around fields in the Niger Delta has made onshore hydrocarbon production activities not to thrive in a clime of increasingly health, safety and environment (HSE) oriented operations leaving most well locations encroached by emerging towns, with flowline right-of-way (RoW) already encumbered.

Sigma field is one of SPDC fields in the Niger Delta that were impacted by third-party encroachment. An initial assessment showed 26 producing oil conduits and 11 RoWs were impacted resulting into production deferment of ca. 10,300 bopd. Given an encroachment resolution cost of ca. US$37mln budgetary provision there was the need to carry out cost-benefit analysis of the additional investment.

This paper presents the approach adopted to get the most out of the field in the Niger Delta whilst countering the effects of third-party encroachment through set criteria: well cluster based on common location, and creaming based on recoverable volume, conduit level reserves and conduit potentials. 19 conduits were recommended for re-opening with a life cycle recoverable volume of 33MMBOE saving US$9.6mln. It was concluded from preliminary economics that the encroachment resolution cost of US$37mln can be accommodated by the additional oil and gas production notwithstanding the rigour required for handling third-party issues.
An Integrated Approach to Reservoir Quality Prediction of Untapped Oligocene Reservoir Offshore Western Niger Delta
Authors: Obinna Chudi , Anaevune Austin , Lewis Helen , Stow Dorrik
Published: July 2016

A belief that has been widely accepted amongst petroleum engineers and geoscientists in the oil industry is that early hydrocarbon emplacement in sandstone reservoirs is capable of inhibiting quartz cementation, thereby leading to porosity preservation. Results from this study of the timing and degree of cementation of a deep Oligocene potential clastic reservoir are used to predict: (1) the onset and volume of quartz cementation in the potential reservoir, and (2) the effect of early hydrocarbon emplacement on reservoir quality. In this study, burial and thermal history of untapped deeper Oligocene plays that lie below the highly productive clastic Miocene plays of the western deep Offshore Niger Delta are investigated using basin modelling enhanced by quartz cementation modelling. Of particular interest is the timing of charge to the reservoirs and the timing of diagenesis. Quartz cementation was modelled using the Walderhaug quartz cementation algorithm as a precipitation rate limiting reaction controlled by the rock fabric and temperature. Model calibration was primarily achived using physical properties measured from well A1- the only well that penetrated the top of the Oligocene sequence.

Simulation results indicate that less than 0.5% of pore space of the shallow proven hydrocarbon-bearing Miocene sands have been cemented, having been exposed only to low temperatures unfavourable for quartz precipitation. This is in agreement with measured porosity values exceedin 30% and permeability in the Darcy range. The deeper Oligocene succession has been buried to depths where temperatures are simulated to exceed 70° C favouring quartz cementation. The cementation model of the Oligocene sediments indicates that less than 14% of the total porosity has been occluded by quartz cement. However, the charge model simulates peak hydrocarbon saturation being reached when less than 7% of the pore space, in all four simulated accumulations, was quartz cemented. Hence the rate of quartz cementation is likely to have reduced from the time of peak oil charge onwards, thereby preserving a significant fraction of the porosity in the potential Oligocene reservoirs.

The integration of all techniques adopted in this study that results in a holistic outcome is believed to represent a novel approach in reservoir quality prediction. If the Oligocene is proven then it would represent a significant new play that is likely to extend beyond the study area across the western offshore Niger Delta.
Technical Evaluations for Reservoir Disposal of Gas-to-Liquid GTL Plant Effluent Water
Authors: Nwume Michael , Oluseye Ekun , Oyinda Onigbogi
Published: July 2016

In compliance with local regulation in Nigeria on open water discharge and environmental stewardship considerations, aqueous Gas-to-liquid (GTL) plant effluents usually treated to meet specification for discharge to the Escravos River were characterized for consistency in quality for disposal by injection into oil/gas reservoirs.

Gas-to-Liquid plant operated by Chevron in the Escravos area has considered the discharge of their aqueous effluent water through the Escravos Produced Water system as an alternative to river dump. These effluents are different in composition and quality with produced water from Oil/Gas reservoirs due to the various sources producing the effluent. To qualify for reservoir disposal, a detailed characterization of the GTL effluent was performed to determine acceptable potential impact on the surface and subsurface facilities.

This paper therefore provides the necessary technical evaluations required for effective reservoir disposal of GTL effluent water when considered to supplement the injection volume or serve as alternative injection water to the conventional produced water re-injection.