|Theme||Visible||Selectable||Appearance||Zoom Range (now: 0)|
Okoro, Emmanuel E. (Covenant University, Nigeria) | Okafor, Ikechukwu S. (Nile University of Nigeria) | Sanni, Samuel E. (Covenant University, Nigeria) | Obomanu, Tamunotonjo (Federal Polytechnic of Oil and Gas, Nigeria) | Oguntade, Tomiwa (Covenant University, Nigeria) | Orodu, Oyinkepreye D. (Covenant University, Nigeria)
A reservoir non-damaging Nano treated aqueous-based drilling fluid was proposed. The study was carried out to obtain a drilling fluid with rheological properties able to keep cuttings in suspension for transport to the surface, minimize filtration and fluid loss. These rheological properties were also predicted using Artificial Neural Network (ANN) due to limitations of existing flow models in predicting Nano-based mud systems. Different concentrations of the Nanoparticles were added to these suspensions of water to act as filtration loss materials. A total number of 160 data were used to train the ANN which consists of both the input data and output data acquired from the experiment. The study shows good agreement between experimental data and the artificial neural network prediction of plastic viscosity (PV) and yield point (YP), for multiwall carbon nanotubes (MWCNT) formulated muds. The addition of different concentrations of MWCNT (0.5 – 3 g) as rheology modifier-additive was put to test in a field applicable aqueous mud system. The developed neural network has a Mean Absolute Deviation (MAD) of 0.61529, MSE of 0.57174, Root Mean Square Error (RMSE) of 0.75614 and Mean Absolute Percentage Error (MAPE) of 1.92331 for the predicted plastic viscosity and yield point which are all indicative of good levels of accuracy. It is important to explore the reservoir impairment mechanisms so as to improve and optimize the reservoir performance during the production of hydrocarbons. Having satisfied all the conditions, permeability was determined using Darcy's equation. A reduction in permeability within the range of 12 – 16 mD was recorded for the Nano treated water-based mud system.
Crude evacuation to the export terminals takes more than 45% of the operating expenditure of some marginal field operators (MFOs) in Nigeria. Many studies on marginal field investment focus more on composite operating cost analysis, hence overlooking its components. Crude evacuation is a major challenge for MFOs because economics of their operations may not support wholistic value chain investment of which crude transportation is a part. Oil pipeline evacuation is the primary onshore crude transportation model available to MFOs. The next option is the virtual pipelines with high risk potentials. Therefore, the market for pipeline crude evacuation becomes a monopoly cemented on several agreements with stringent terms and conditions. One recurrent feature in most of these agreements is the charge on the reserved production capacity (RPC). This cost takes more than 70% of the ullage value in a typical marginal field budget. Are there ways to navigate past this monopoly? This paper seeks to explore economics of various crude evacuation options available in the marginal field terrain onshore and develop integrated evacuation models to highlight the effect of the idiosyncratic monopoly to profitability. The approach x-rays the various crude handling, transportation, terminaling and sales agreements available to MFOs. Hydrocarbon accounting model is incorporated for both pipeline and virtual pipeline evacuations. Iteration of tariff charges and injection split optimization are done on the integrated model. Forecasts are carried out in the face of changing oil prices, oil injection profiles and crude agreements terms and conditions over a period to ascertain the effect on the MFO's bottom-line. The model may be used for policy formulations, sector regulations and the marginal field investment analysis.
Osayande, Francesca (Shell Nigeria Exploration and Production Company) | Oguntola, Somime (Shell Nigeria Exploration and Production Company) | Sonde, Adenike (Shell Nigeria Exploration and Production Company) | Biambo, Tamunotonye (Shell Nigeria Exploration and Production Company) | Osho, Olaseni (Shell Nigeria Exploration and Production Company) | Okpako, Kelvin (Shell Nigeria Exploration and Production Company) | Musa, Joel (Shell Nigeria Exploration and Production Company) | Anaevune, Austin (Shell Nigeria Exploration and Production Company) | Mora-Glukstad, Miguel (Shell Nigeria Exploration and Production Company) | Yamusa, Idris (Shell Nigeria Exploration and Production Company)
The Kangaroo is a field located in the Deepwater Nigeria in water depths ranging from 950 to 1,500 meters. Structurally, the field can be described as a NW-SE trending shale-cored anticline with crestal faulting. Several wells have been drilled encountering primarily oil, in a series of Upper to Middle Miocene channelized turbidite reservoirs. The Kangaroo field is a brown field with challenges of unlocking its full potentials. The key subsurface uncertainties identified, were sand distribution and intra-reservoir connectivity. The existing reservoir models did not fully describe the reservoir net sand thickness and as a result, recent drillings have highlighted series of surprises warranting a study, to gain more insights into the sand distribution and reservoir heterogeneity.
This study highlights a multi-stack simultaneous seismic inversion used in conjunction with rock physics analysis, for a detailed reservoir characterisation, re-mapping of key reservoirs and prediction of Net-to-gross away from well control. Five offset angle seismic sub-stacks have been inverted with a Simultaneous Inversion algorithm, ultimately converting the reflectivity seismic data into rock property models, generating acoustic impedance (Zp), shear impedance (Zs), and density (ρ).
A feasibility study including crossplots of petrophysical and elastic properties from well data was carried out to establish rock property relationships in the interval of interest and this formed the basis for the seismic inversion studies. Key business driving value for this study, is the derivation of a robust estimates of net sand distribution, its impact on modelling reservoir parameters, and consequent estimation of in-place volumes.
Efficient Project Management in Digital Oilfields (DOF) space usually focus in addressing the asset business challenges through clearly defined business objectives for the project implementation. One of the key reason why such digital oilfields project implementation fails is because most operating asset use the ‘conventional project management approach’ in dealing with digital oilfields implementation. The ‘Conventional Project Management’ approach rest the entire responsibility of managing the project on the Project Manager who is normally NOT a member of the business or asset. This Project Manager usually abandons this role of managing the implementation after ‘Go Live’ or on ‘completion’ of the project. The objective of this presentation is to identify the reasons why the ‘conventional project management framework’ fails and proffer a field-tested project management approach that ensures seamless embedment of the Digital Oilfields Transformation solutions.
A field-tested approach is demonstrated through research work in a field where a Business Opportunity Manager (BOM) who is a member of the business (not from the project team) who actually anchored the implementation of digital oilfields solutions in an asset in Gulf of Guinea. The Business Opportunity Manager actually interfaces between the business and the project team right from inception of the project through into the handover of the project to the business thereby ensuring seamless embedment and sustainability of the realised solutions for continuous business improvement.
Digital Oilfields (DOF) Transformation is a continuous business improvement initiative in project management. The results show significant business benefits from this option of using the Business Opportunity Manager from the business in delivering the solutions rather than the conventional project manager that takes overall management of the project and leaves on ‘completion’ of the project implementation. The gains or value proposition from the DOF implementation are sustained and continuously improved with solid embedment process. This result will serve as reference tool and assist Digital Transformation experts build a sustainable framework in similar project implementation and management, globally.
Almabrok, Almabrok Abushanaf (Sirte University, Libya) | Aliyu, Aliyu M. (University of Huddersfield, HD1 3DH, UK.) | Baba, Yahaya D. (The University of Sheffield, UK) | Ribeiro, Joseph X. F. (Kumasi Technical University, Ghana) | Archibong-Eso, Archibong (University of Birmingham, Dubai, UAE) | Lao, Liyun (Cranfield University, Bedfordshire) | Yeung, Hoi (Cranfield University, Bedfordshire)
Pressure gradient (PG) is vital in the design/operation of process equipment e.g. in determining pumping requirements and has direct effect on capital and running costs. Here, we report a gas–liquid experimental study using a large diameter pipeline system. Pressure was measured at two locations of each section of the upward and downward flowing sections. PG was then determined for a wide range of superficial velocities:
Sulaimon, Aliyu Adebayo (Department of Petroleum Engineering, Universiti Teknologi PETRONAS, Malaysia) | Umar, Abubakar Abubakar (Department of Petroleum Engineering, Universiti Teknologi PETRONAS, Malaysia) | Sulaimon, Abdul-Azeez Oladimeji (Department of Statistics, University of Ibadan, Nigeria) | Masri, Asiah Nusaibah (Department of Chemical Engineering, Universiti Teknologi PETRONAS, Malaysia) | Bello, Kelani Olafinhan (Department of Petroleum Engineering, University of Benin, Nigeria)
Asphaltene deposition constitutes a major flow assurance challenge during oil production. Several attempts have been made to predict asphaltene stability using SARA analysis, which is usually expensive and time-consuming. Therefore, we have developed new SARA-independent correlations for the colloidal instability index (CII) and the refractive index (RI) as functions of oil density. The new density-based CII or DBCII is proven to be reliable with an average absolute relative error (AARE) of 0.1428, standard deviation (SD) of 0.1902 and a correlation coefficient R2 of 0.9520. Similarly, density-based RI or DBRI has been validated with an AARE of 0.0037 and SD of 0.0044. Two new deposition envelops have been developed with different criteria. The stable regions are characterized by DBCII lesser than 1.1 and DBRI greater than 1.525 while the unstable zones are defined when DBCII is greater than 1.8 and DBRI lesser than 1.503. The metastable region is identified within the limits of stable and unstable criteria. Comparative analyses have shown that the new correlations are simpler, cheaper and more accurate than the existing SARA-fractions-dependent-RI correlation and molecular-weight-dependent CII correlation.
Sulaimon, Aliyu Adebayo (Department of Petroleum Engineering, Universiti Teknologi PETRONAS, Malaysia) | Masri, Asiah Nusaibah (Department of Chemical Engineering, Universiti Teknologi PETRONAS, Malaysia) | Shahpin, M. Hazri (Central Analytical Laboratory, Universiti Teknologi PETRONAS, Malaysia) | Salleh, Intan Khalida (PETRONAS Group Research & Technology, Malaysia) | Sulaimon, Abdul-Azeez Oladimeji (Department of Statistics, University of Ibadan, Nigeria) | Bello, Kelani Olafinhan (Department of Petroleum Engineering, University of Benin, Nigeria)
Formation of gas hydrates in oil and gas production systems constitutes a major flow assurance challenge and the consequences to the smooth production operation could be catastrophic. Recently, there is a shift of focus from total hydrate prevention to risk management which is more economical with reduced storage and injection facilities. Therefore, we have formulated two novel imidazolium-based Ionic Liquids (IM-based ILs) for thermodynamic methane hydrate inhibition. Heating, insulation, and addition of thermodynamic or kinetic inhibitors are strategies to prevent hydrate formation. The COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) was used to screen and rank several potential IM-based ILs based on their hydrogen bonding energies. 1-ethyl-3-methylimidazolium glutamate (EMIM-GMT), 1-butyl-3-methylimidazolium glutamate (BMIM-GMT) and 1-(3-cyanopropyl)-3-methylimidazolium glutamate (CPMIM-GMT) with hydrogen bonding energies of −62.01 KJ/mol, −61.46 KJ/mol and −67.21KJ/mol respectively were selected and synthesised for performance evaluation. Methane gas of 99.995% purity was used with deionised water to conduct thermodynamic dissociation tests using the SETARAM micro-Differential calorimetry (μDSC 7 Evo-1A). The μDSC was calibrated by comparing the offset dissociation temperature data of deionised water with published data from the literature. Thereafter, the dissociation profiles were obtained at pressures 30, 50, 75, 100, 125, and 150 bars. Results show that for 0.1wt% of the three IM-based ILs, the dissociation temperature increases with pressure and a good thermodynamic inhibition with temperature shift in the range from 0.87 to 1.14°C was observed. The EMIM-GMT achieved the highest geometric average temperature shift of 1.14°C while the CPMIM-GMT and BMIM-GMT shifted the hydrate dissociation envelop by 0.91°C and 0.87°C respectively. Thus, the thermodynamic inhibition performance of EMIM-GMT is better than most of the current EMIM- and BMIM- Halide groups of IM-based ILs with the individual and combined average shift of less than 1.0°C. In this study, we have shown that the effectiveness of an IM-based IL as a thermodynamic methane hydrate inhibitor is largely a function of its hydrogen bonding energy between the water molecule and the IL ions. The relative order of performance of the three IM-based glutamate ILs is EMIM > CPMIM > BMIM.
Inemugha, Olanari (World Bank Africa Center of Execellence, Center for Oilfield Chemicals Research, University of Port Harcourt, Nigeria) | Chukwuma, Franklin (Department of Chemical Engineering, University of Port Harcourt, Nigeria) | Akaranta, Onyewuchi (World Bank Africa Center of Execellence, Center for Oilfield Chemicals Research, University of Port Harcourt, Nigeria) | Ajienka, Joseph A. (Department of Petroleum and Gas Engineering, University of Port Harcourt)
Polymers are known for controlling fluid loss and modifying rheology in drilling muds through polymer chain entanglement and polymer-solvent interactions. Natural polymers have been used in the formulation of drilling muds, mainly due to their high molecular weight and eco-friendliness but they have limitations in controlling fluid loss, modifying viscosity or forming good gel strength in saline and thermal environments. This study reports laboratory evaluation of Terminalia mantaly exudates as viscosifier in drilling mud formulations. The effects of polymer concentrations, temperature, pH and salinity on the rheological properties of this novel biopolymer were investigated. Results obtained show that as polymer concentration increases (0.5% – 2.5%w/v), the rheological properties (apparent viscosity, plastic viscosity and yield point) of the biopolymer increased. At the polymer concentrations investigated, an increase in temperature (80°F-150°F) results in a slight decrease in the rheological properties of the polymer. At 2%w/v polymer concentration, an increase in salinity results in a slight decrease in its rheological properties, while at 1.5%w/v polymer concentration, an increase in pH (4-10) shows no significant change in the rheological properties. The shear stress increases with increase in shear rate and obeys the Bingham plastic model. The results obtained show that the polymer has a good alkaline resistance at pH above 7 and stable rheological properties at increased salinity and temperature. This has been attributed to the stable repulsive forces of the negatively charged polyelectrolyte of the polymer as salinity increases. From the results obtained in this study, Terminalia mantaly exudate can be a substitute for conventional natural polymers in water-based drilling muds.
Unstable boreholes due to tensile & shear failure results in serious drilling problems. This increases the non-productive time spent in the field and the cost of reviving failed wells in the oil and gas industry in order to mitigate or prevent borehole failure, different rock strength criteria models have been developed to predict the optimum required mud weight but unfortunately, not all models fit for all formation considering the different drilling conditions, hence these models need to be evaluated to check their validity and accuracy for drilling stable wells in the Niger Delta. To achieve this purpose, collapse and fracture pressure that defines the lower and upper boundary of a mud weight window are calculated using derived formula equations from three failure criteria models; Hoek-Brown failure criterion, Mohr-Coulomb failure criterion and Mogi-Coulomb criterion failure criterion. This is achieved using Microsoft Excel and the simulation is done on a plot to show the different mud window by each model for comparison. The input parameters relevant for this study are pore pressure, in-situ stress data and rock mechanical properties which were acquired from a high-pressured zone in an xxx-onshore oilfield of the Niger Delta. A plot of the predicted optimum mud weight vs the actual mud weight against depth is compared to check the accuracy of each model to conclude on the failure criterion that is best fit for the formation in this field. The results showed that Hoek-Brown failure criterion gave an unrealistic outcome, when used to drill will lead to borehole breakout. Mohr-Coulomb and 3D Mogi-Coulomb criteria gave similar results which can be used but Mogi-Coulomb is recommended for drilling stabilized vertical wells due to the consideration of intermediate principal stress effect on rock strength over the conservative Mohr-Coulomb.
Menegbo, Edward K. (Petroleum Engineering Department, University of Port Harcourt) | Charles, Eme (African Centre of Excellence for Oilfield Chemicals Research, University of Port Harcourt) | Dosunmu, Adewale (Petroleum Engineering Department, University of Port Harcourt)
The efficiency of cuttings transport is very important factor for a good drilling operation program. The transportation of these cuttings through the annulus is a complex problem that is affected by many parameters. For effective cuttings transport prediction, it will require that all these parameters be considered simultaneously. Predictions of pressure losses and cuttings transportation through the annulus are very complex during drilling operation due to the combination of interacting drilling parameters. Success during drilling program is due to efficiently cleaned hole. For better understanding of the effects of some of these parameters that affect cutting transportation, the power law of non-Newtonian viscosity model was adopted to establish the mathematical model of the cutting transport process in the well annulus. Some of the hole-cleaning challenges focused are: the absence of the basic data needed to fully evaluate present field practices and current concepts on drill cutting transport, the combined effect of operational parameters and drilling fluid properties, the effect of operational parameters and cutting properties and what is the effect of rheology model on cutting transport simulation. Poor hole-cleaning during drilling can lead to a lot of bore hole issues which has a negative effects. The overall effect is increase in drilling time and drilling cost. The proposed tool allows more precise prediction of cuttings transport property in the whole range of the well. In this paper, the effects of annular fluid velocity, transport ratio, size and density of cuttings are investigated. The results obtained showed that the most important factors controlling cutting transport are annular velocity and the fluid rheological properties. From the simulation result, it can be observed that an optimum transport ratio was obtained at 1.42m/s. The transport ratio increases rapidly with velocity but then begins to level out or increase more slowly in the velocity range of 1.42 to 1.62 m/s. We can also deduce from the result that cuttings velocity increases with the flow rate; but this increment does not follow a linear behaviour.