bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation Resistivity Theory: How Archie Equations, Shaly Reservoir Models, Conductive Rock Matrix Model and Dual/Triple Porosity Models are Related
Authors: Iheanacho Philip C. 
Published: July 2013

Abstract
Estimation of hydrocarbon pore volume, HCPV, from resistivity logs can be quite troublesome in some complex heterogeneous reservoirs. Most water saturation-formation resistivity models that work well for some reservoir give unreliable results for others. No single model works for all types of reservoirs scenarios.
This paper presents the theory of formation resistivity in porous media. The paper develops the theory from the parallel resistivity model and then extends it for series resistivity model.
When applied for clean sand, the theory derives Archie equations from first principle. The derivations show that both porosity exponent and saturation exponent are of the same origin and should have the same name. A better name for both parameters should be tortuosity exponent of a component with respect to its fraction in a control volume. It is also advantageous to treat as a single parameter rather than two separate parameters.
In addition, this theory derives new shaly sand models for estimating HCPV. These new shaly sand models can be used for different type of shale distribution by adjusting the value of a single parameter in the models. The formation resistivity theory is also used to derive formation resistivity models for conductive rock matrix reservoirs and dual/triple porosity reservoirs. A new equation for calculating composite porosity exponent is also developed.
Field data are used to validate this work. The theory, when applied for each scenario, derives formation resistivity models for estimating reliable HCPV of different reservoir scenarios and types. Moreover, the strength of this theory is its ability to generate models that closely resembles models that have proved to work well for the reservoir cases for which they were developed. Although this work does not test the theory for the cases of tight sand, shale gas and other unconventional reservoirs due to unavailability of such data, there is a strong possibility that it would work for such reservoirs if the necessary data were available.
Petroleum Reservoir Characterisation for Fluid with Yield Stress Using Finite Element Analyses
Authors: Farayola K. K. , Olaoye A. T. , Adewuyi A. 
Published: July 2013

Abstract
Flow behaviour of Newtonian fluids in different discrete fracture geometry orientations has been studied by several researchers. Not all reservoir fluids can flow easily with its inherent energy, and producing such fluids can be very difficult. Some forces, for example yield stress, greater than a threshold value need to be exceeded to achieve flow of these fluids. The flow channel can either be through interconnected pore spaces or discrete fractures. Because of variation observed in geometry of real fracture systems in naturally fractured reservoir, NFR, flow computation of these fluids in fractured media is full of difficulty.
This paper reports the flow behaviour of Bingham plastic and Herschel-Bulkley fluids in discrete fractures oriented at θ = 0°, θ = 20° and θ = −20° represented on a 1m dimensioned fractured block using finite element analyses. Each fracture orientation has its associated pressure gradients which result in flow of fluids. Our approach is the discrete fracture network (DFN) where fluid flow into the wellbore is only through fractures, which are surrounded by an impermeable rock matrix.
Flow through fractures in naturally fractured petroleum reservoir has been observed to contribute to overall production of fluid from the reservoir through the wellbore to the surface. The results obtained from similar orientations of discrete fracture geometry for Bingham plastic and Herschel-Bulkley fluids are compared to results obtained for power law and Carreau models by Fakinlede et al. (2011). Results comparison is later extended to Newtonian fluids. The flow of yield stress fluid has applications in the in-situ recovery of bitumen from oilsands reservoir since the bitumen will not flow unless the yield stress is exceeded.
Laboratory Studies of Chemicals for Sand Consolidation (Scon) in the Niger Delta Fields
Authors: Abanum Andrew M. , Appah Dulu 
Published: July 2013

ABSTRACT
Sanding during oil production causes severe operational problems in the oil and gas industry. Several techniques have been used for sand production control in sandstone reservoirs. Consolidating materials, such as, crude oil coke and nickel plating have been used in the past by researchers. At present, the chemical binders, such as; phenol resin, phenol-formaldehyde, epoxy, and furan or phenol-furfural provides cementation. This work is centered on the laboratory studies of selected sand consolidating resins that would be suitable for application in the Niger Delta (ND) oil fields. Considering the available resins for consolidation process, six types of chemical resins namely; Epoxy (A&B), Novalak Phenol-Formaldehyde, Furan Phenol Acrylic, Furan and Phenol resins were selected for studies. Three other locally made resins: Rubber Latex, Evo Stik and Polystyrene gum were reviewed alongside for comparison and test for their applicability. Different core samples were made by mixing these resins and their hardening agents with sand sample obtained from a sand producing oil field in the Western Niger Delta. The core samples made were subjected to laboratory qualitative and quantitative analysis in order to obtain individual permeability and porosity under different overburden pressures from 500psi through 3500psi. Results from experimental data show that Epoxy A&B resins ranked best followed by Furan resin and then, the local resins. This was adjudged based on minimal variation in the permeability and porosity of the core samples retained in acceptable values after curing and by analytical result from measurements at various overburden pressures.
INTRODUCTION
Unconsolidated sandstone reservoirs are most susceptible to sand production, especially those with permeability between 0.5 to 8 Darcies. Sand production in such reservoir may start during first flow or later when reservoir pressure has fallen or water breaks through. Most of the world's hydrocarbons are located in unconsolidated reservoirs(1,2). These rocks are usually relatively young in geologic age, and are unconsolidated because natural processes have not cemented the rock grains together by mineral deposition(3,4,5). Sand production occurs with varying degree of severity, not all of which require action anyway. The rate of sand production may decline with time at constant production conditions and is often associated with cleanup after stimulation. Very soft formations may exhibit sand production at the time of initial discovery; the so called "sloughing?? sands can lead to great difficulties during completion operations when bore-hole collapse can become a major problem. Many others, normally somewhat more consolidated formations begin to show sand production after a considerable period of production - due to reservoir pressure depletion (decrease in minimum in-situ stress), water production, increased fluid velocities etc.
Detrimental Effects of Acetic Acid on Corrosion of Carbon Steel Pipelines Transporting Wet Gas
Authors: Ajayi Fredric , Lyon Stuart 
Published: July 2013

Abstract
The integrity of pipelines transporting wet gas has been a concern to oil and gas industry in recent times. Top of the line corrosion (TLC) in particular is important because of the inability to protect the upper wall of pipelines (i.e. in the vapour space) with conventional corrosion inhibitors. Organic acids, such as acetic, are volatile components in oil and gas reservoirs and play significant roles in determining the corrosion process that occurs at the 10-2 o'clock position of the pipelines. TLC of a typical carbon steel pipeline containing 1% NaCl (containing acetic acid) saturated with CO2 gas at 60°C for a period of 100hrs was investigated by applying electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and linear polarisation resistance to mild steel samples exposed to these conditions. Both CO2 and acetic acid are transported in the gas phase and condensed with water thereby contributed to corrosion processes at the top of the line. Preliminary results demonstrated a progressive reduction in corrosion rate with time in the CO2 environment indicated by an increase in the polarisation resistance. However, with the introduction of acetic acid the corrosion rates increased significantly. The results of this study will form the basis of an understanding of the corrosion experienced at the top of the line and determining the amount of corrosion inhibitors to be injected using V-Jet™ pig in similar field environment to prevent carbon steel pipeline failure, and subsequent oil spillage.
Geomechanics: Modeling Wellbore Stability While Drilling Through A Parallel Weak Bedding Plane; Case Study Of Highly Inclined And Horizontal Wells
Authors: Bassey Akong , Dosunmu Adewale , Otutu Friday 
Published: July 2013

Abstract
The drilling of an oil well in an area of geological complexity presents many challenges in the planning and drilling phases. These complexities included a highly-deviated well profile, dipping formations, and naturally fractured formations. Moreover, the wellbore challenges were compounded by the high stresses in a tectonically-active area. Thus, to help ensure successes of drilling operation, it is necessary to incorporate new technologies to define the risk that the drilling case presented and to prepare for the potential problems predicted in the pre-well planning. Geomechanical modeling for wellbore stability can address the different conditions that constitute this type of well. However, in order to quantify the effect of the variables mentioned above (drilling parallel to bedding planes in a shale formation and drilling through a naturally fractured formation), it is necessary to have fracture porosity and permeability data, fluid viscosity inside the fractures, poroelastic parameters like undrained Poisson, Biot coeffient to model the weak bedding effect, and strength parameters like cohesion and the friction angle of the bedding planes and bedding plane orientation that account for the angle of attack analysis (angle between the well and the bedding plane) (Aadnoy et.al 2009). This paper analyzes the bedding plane failure which is base on the linear elastic and isotropic model for stresses around the wellbore, with the aim of trying to understand the general behavior of inclined boreholes due to anisotropy using the several case studies. The analysis remarkably found that for a laminated rock (sand/shale stringers), a weakness of a plane may subject the well toward collapse for the hole angles between 10 to 40deg (Aadnoy and Chenevert 1987). The model also analyzes the 3D effect of attack angle with changing azimuth for a constant inclination on bedding plane exposed horizontal wells. It is seen that bedding exposed does not only depends on inclination but also on the dip of the formation, attack angle and well azimuth. The model also categorized geomechanical operational scenarios into three while drilling complex weak bedded horizontal wells, and this include pre - drilling (pore pressure prediction, mechanical properties, and stresses), while drilling (real - time monitoring at the rig site to obtain geomechanical properties from petrophysical logs), and Post - drilling (logs, and offset events documented). Finally, the model results defines the optimized well path, integral mudweight envelope (geomechanical window), wellbore diagnosis and also ensure whether the horizontal well data has existed on the bedding exposed or protected positions. All these will help in reducing NPT (non productive time) wellbore instability related stuck pipe incident.
Development of Semi-Analytical Post-Breakthrough Predictions for Vertical and Horizontal Wells
Authors: Ike I.A. , Debasmita M. 
Published: July 2013

Abstract
Horizontal and vertical wells are commonly used in the production of oil lying above a water zone, or above a gas zone or sandwiched between the gas and the water. Under such conditions, water or gas coning is a very common problem. Experimental, empirical and analytical works have been done in determining the critical oil production rate and the breakthrough time if production is supercritical. Aside from numerical simulations, post-breakthrough production predictions have been restricted to experimental and empirical techniques employing statistical regression.
In this work, employing analytically derived breakthrough time expressions for vertical and horizontal wells, a technique have been developed to semi-analytically predict the rate of oil and water production after cone breakthrough in vertical and horizontal wells. The results of this new procedure were compared with predictions from numerical simulations and some common literature correlations. Though the analytical technique tended to under-predict oil production, it presented a trend which conformed more to the numerical simulation results than the correlations tested. It thus can be used for checking more complex numerical simulations and can serve as a backbone for developing consistent post-breakthrough correlations.
Simplified correlations for the determination of breakthrough time for vertical and horizontal wells were also developed from the semi-analytical formulations. To the best knowledge of the authors, this is the first semi-analytical post-breakthrough modeling of vertical and horizontal wells.
Introduction
Work on coning had generally been pursued along the path of preventing or delaying cone generation and evolution, the time to breakthrough if advancement is not checked and the performance of the well after cone breakthrough. A number of empirical and analytical studies have been conducted to model and determine these properties (Joshi, 1991). Correlations and models for the determination of critical rate of oil production, time to breakthrough when producing at super-critical rate and the performance of the well after breakthrough have been developed for vertical and horizontal wells. These models may be experimental, empirical or analytical. After breakthrough performance model available are generally not analytical.
Development of a Computer Program for Solids Control
Authors: Adjimah M. J. 
Published: July 2013

Abstract
Computer software is used extensively to increase productivity and reduce man-hours of labour. This work presents the development of a simple solids control software (SOLCON) which is designed for real time mud system management and quick performance of routine rig computations: determination of total solids and low gravity solids content; mud property and density control requiring optimal ejection rate into the mixing pit; volume of mud and amount of barite, bentonite and additives to be added during the upgrading process of the mud. This software has the ability to evaluate the need for dilution depending on the maximum allowable drilled solids, viscosity and recommended total solids in the drilling fluid.
In addition, a procedure for determining the actual drilled solids that remains in the drilling fluid after routine solids control using the 200 and 150 mesh size shale shaker has been developed to enhance efficient control of drilled solids.
The Changing Face of Global Oil and Gas Production and its Implication on Nigeria
Authors: Ike I. A. , Leo M. 
Published: July 2013

Abstract
The media are awash with discussions of the US becoming the largest oil producer in less than a decade and to be self-sufficient in energy in about two-decade's time. That means a lot for Nigeria since the US has been the largest buyer of Nigeria's crude oil. Losing one's largest customer only to see the erstwhile customer becoming a major competitor is a dreaded nightmare for any business outfit. India and China may not necessarily have the capacity to buy off what the US is predicted to leave off as there are potentially new players like the countries of East Africa, Brazil and Canada coming on the scene or strengthening their hold on the market. It is also important to note that the shale business may also thrive in China, a country that is estimated to have the largest shale gas reserve. This paper investigates the far-reaching implication of these strategic developments and prospects on the future of oil and gas production in Nigeria and on the Nigerian economy which is currently heavily dependent on petroleum revenue. It concludes that Nigeria can only have a chance if it aggressively increases it local energy utilization and become more competitive in the oil and gas business by improving community integration and environmental responsiveness, transparency, professionalism and efficiency.
Modelling Formation Damage Induced by Propagation of Single-Phase Non-Newtonian Polymer Solution in Porous Media
Authors: Idahosa P. E. , Oluyemi G. F. , Oyeneyin M. B. , Prabhu R. 
Published: July 2013

Abstract
Non-Newtonian high molecular weight polymers dissolve in water to increase viscosity for stable displacement of oil and gas by injected water and enhanced sweep recovery. In both microscopic and macroscopic description of geological factors controlling delivery of oil and gas from reservoir to wellbore, and hence, total eventual production, permeability is a dominant factor. Despite the role of polymers in enhancing oil recovery, polymer adsorption on rock surfaces can also cause permeability reduction, and hence, oil and gas productivity decline due to flow restrictions (formation damage). In the literature, studies on selective permeability reduction (with emphasis on mobility reduction and residual resistance factors) by polymer adsorption based on constant absolute permeability assumption are well known. However, even then, these studies are based on mathematical expressions and formulations that are subjective. There is therefore no existing model that fully considers a combination of the effects of polymer adsorption and its non-Newtonian behaviour on absolute permeability during single-phase propagation in porous media. In order to describe single-phase non-Newtonian flow in porous media, a macroscopic flow rate/pressure drop relationship that combines a mathematical description of fluid rheology must be developed. In this paper, a new method is developed in order to investigate and characterize absolute permeability alteration due to the propagation of single-phase polymer solutions in porous rock media. The validity of the proposed model is demonstrated by using experimental data sets involving single-phase polymer flooding with varying concentrations and formation permeabilites.
Entrepreneurship & Small Business Start-Up
Authors: Efemena Doroh , Monye Benedict 
Published: July 2013

Abstract
For effective growth of Oil & Gas Production in Africa, there is need for workable policies, funding by Government, Agencies and Multinationals, establishment of Oil & Gas Industrial banks and the lowering of lending and interest rates, giving of grants to screened and trained would be entrepreneurs, the collaboration of local entrepreneurs with foreign technological companies, investment in local innovations and technologies, development of similar techniques and software, investment in ICT, training and preparation of employees on entrepreneurship towards retirement and human capital development.
According to Robert T. Kiyosaki, author of Rich Dad Poor Dad, financial struggle is often directly the result of people working all their life for someone else. Many people will have nothing at the end of their working days. Perhaps this attitude, which is also common amongst most African nation citizenry, is a product of colonialism on the colonized generation, but that is not an excuse to continue at it if their economy must improve. Philip Adams once said. Most people can do extraordinary things if they have the confidence or take the risks. Yet most people do not. They sit in front of the internet, television and treat life as if it goes on forever.

Conclusion
Starting and operating one's own business has been becoming an interest area for individuals from different stock of life. Therefore entrepreneurs should acquire desired knowledge, skills, and competencies that would enable them to become confident entrepreneurs who are capable of creating innovative important business ideas. The various governments should also put things in place.
Valuation Of Renewal Bonus For Expired Leases
Authors: Babalola S. A. , Ogunnubi O. B. 
Published: July 2013

Abstract
The determination of Renewal Bonus has been the concern of the Department of Petroleum Resources. Renewal Bonus is the amount to be paid by leaseholders to Government for the renewal of expired leases. The challenge has been which technical criteria should be used for an equitable determination of the bonus to be paid to ensure industry-wide acceptance.
To overcome this concern, an economic model was developed and fine-tuned using already existing fiscal terms. The model was made robust by using actual oil, gas and condensate production data over the life of the block, the company's projection of the performance of the blocks over the next five years that is acceptable for business decision making and its further estimates for fifteen years to cover the twenty year renewal period, assuming its license renewal is approved.
The economic model was run using existing fiscal terms together with the concession's historical OPEX, CAPEX, and annual production. The ultimate recovery and reserves of the fields within the block was also utilised. The model then determined the NPV for liquid (oil and condensate) and gas (Associated and Non Associated Gas) over the twenty-year renewal period. The model was run over the block life covering periods before expiration up to the new twenty-year renewal time and beyond.
Company equity and logically derived Renewal Bonus Constant was used to compute the amount to be paid by the operator. Sensitivities were run on the model to determine the best-case scenario for liquids, gas and BOE (for a combination of liquids and gas) that could enable the DPR management make appropriate, fair and therefore acceptable recommendation to the Honourable Minister of Petroleum Resources (HMPR).
The result of the Renewal Bonus for each company suggested consistency when the plots of Renewal Bonus against the BOE for all the companies were made.
This paper is intended to give insight to the fairness of the DPR in technical decision making that have led to effective advice to government.