bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Salinity and Divalent Ions on Local Bio Polymers
Authors: Obuebite A. A. , Onyekonwu M. O. , Akaranta O. , Uzoho C. U.
Published: October 2018

Polymer flooding, an aspect of Chemical Enhanced Oil Recovery has proven to be effective in mobilizing residual oil and increasing sweep efficiency thereby contributing to an additional oil recovery of about 20%. However, recent studies have shown that local materials capable of acting as biopolymers have high potentials in enhancing oil recovery. This has attracted more interest due to their low cost, availability and environmentally friendly nature. This study seeks to evaluate the effect of polymer concentration, salinity and divalent ions on local biopolymers.

Three different local biopolymers namely Okro (Abelmoschus Esculentus), Ewedu leaf (Corchorus) and Editan leaf (Lasianthera Africana) was evaluated in the laboratory at varying concentrations. Two high salinity synthetic brines, labelled Soft Brine and Hard brine was also prepared in the laboratory to simulate actual formation brine. Aqueous stability and salinity scan experiments were conducted to determine compatibility and salinity tolerance of the local biopolymers with the different brines. Unconsolidated sand-packs oil displacement experiment was performed with medium crude using local polymer prepared in soft brine and hard brine solution to determine the effectiveness of the polymers.

Results showed that the various local polymers were compatible with soft brine, while compatibility with hard brine was highly controlled by the pH. As the brine salinity increased, the pH of the biopolymer concentration decreased. More so, as the concentration of the local polymer increased from 1000ppm-5000ppm, the displacement efficiency for each of the polymers increased. The effect of salinity during flooding showed that at higher salinity, the recoverability of the various polymer decreased. Sand pack flooding results showed that of the three local polymers, 0.5wt% Okro (Abelmoschus esculentus) gave the highest additional recovery of 23.4%OOIP. Polymer flooding with soft brine gave a higher displacement efficiency compared to hard brine flooding due to the presence of divalent ions with magnesium ions having the greater effect. This study supports the fact that at increased salinity and the presence of divalent ions leads to mechanical degradation of the local polymer which reduces the viscosity and increases the adsorption of the polymer solution thereby reducing the sweep/displacement efficiency of the polymer.
Application of Pressure Transient Well-Test to Geologic Reservoir Characterization of a Turbidite Reservoir in the West African Transform Margin Basin Offshore Cote d'Ivoire
Authors: Keshinro Olalekan , Adeyemi Quadri Arasi , Oni Olugbenga , Sonibare Wasiu , Ramaswamy Sunil
Published: October 2018

Building static reservoir model that realistically captures facies heterogeneities relies on detailed interpretations of the sand body architectures from the integration of subsurface datasets and analogue examples. The delineation of stacked channelized turbidite sands was carried out, based on detailed petrophysical analysis, well log correlation and seismic interpretations. The continuity and connectivity of these sands remain a challenge despite having carried out detailed seismic attribute analysis for sand fairways mapping. For this study, we used a combination of well logs correlation and pressure transient analysis to resolve the sand connectivity and continuity challenges.

Pressure transient analysis can be used to achieve both well productivity analysis and reservoir dynamic descriptive analysis. Interpretation of pressure transient well test can be done either by type curve matching or log-log derivative plot. A combination of log-log derivative plot and the Tiab Direct Synthesis (TDS) method were used to analyze the well test data. A log-log derivative plot is a plot of the pressure derivative against time with both axes on a logarithmic scale. Different geologic features such as faults, fractures and sand channels show unique fingerprint on the log-log derivative plots.

The distance of the channel sand from the well was estimated using the Tiab Direct Synthesis method by making use of the gradient of the channel fingerprint on the log-log-derivative plot.

The well test data from two wells at approximately 2.5km apart were plotted on the log-log derivative plot in other to identify the nature of the geologic features around the wells. In one of the well, channel sand signature or fingerprint was seen and the other well was not tested long enough to see the channel sand signature on the log-log derivative plot. The gradient from the channel sand signature on the log-log derivative plot was used in the TDS model to estimate the distance of the channel sand from the well. The TDS model estimated the distance of the channel sand from the well to be 51m. Based on the result of the pressure transient test analysis, we could establish that the sand is not continuously connected between the two wells. In combination with well logs correlation and seismic attribute analysis, the established sand fairways and baffles thus led to robust geological models with petrophysical properties that capture properly the lateral heterogeneity in the field.
Coring Unconsolidated Formations under Challenging Drilling Conditions – A Case Study, Swamp- Niger Delta.
Authors: Onyeji J. A , Abdullahi N. U , Owoyemi B , Ekun O. A , Akhigbemen E , Ajaegwu N
Published: October 2018

In the drive for excellent reservoir management practices and optimizing oil and gas production through efficient reservoir performance, the role of conventional coring cannot be overemphasized. Core data provides most representative and relevant data for the interpretation and understanding of the subsurface. Continuous coring techniques were deployed in the study area to obtain high quality cores for analysis and reservoir characterization of the productive intervals and development of appropriate enhanced oil recovery strategy. The reservoir cored is characterized as poorly consolidated sandstone reservoir comprising of a calcite roof, moderately sorted and very fine-grained, friable and laminated with shale. A thick column of shale intercalation separates the reservoir into upper and lower lobes. Generally, the formations were characterized as weak with the sand minimum stress of 7.5ppg to 11.0ppg and shale collapse pressure of 8.5ppg to 11.5ppg. Some of the challenges encountered in coring this reservoir includes but not limited to the following: Well collision issues, wellbore instability, depleted reservoirs, selection of effective coring bottom hole assembly and drilling fluid as well as rig space constraints. This paper presents how innovative techniques aided in mitigating the challenging drilling conditions. The systematic approach deployed comprises the use of gyro survey while drilling (GWD), anti-collision analysis, utilization of well-designed drilling fluid with low invasion properties that still maintain wellbore integrity and stability. A close monitoring of equivalent circulating density (ECD), use of fiberglass inner core barrel and low fluid invasion system that comprises core heads with special fluid pass ports to deviate flow away from already cut cores, and full core catcher system was employed. A detailed stratigraphic correlation with the offset wells to identify vital stratigraphic markers was carried out prior to coring. A 15 feet hole was drilled into the calcite roof of the reservoir with PDC bit and the hole cleaned prior to pulling out of hole with the drilling bottom hole assembly (BHA) to minimize the risk of core jamming. Cores were cut with special selected coring BHA using controlled coring parameters while plotting inverse rate of penetration (i-ROP). In addition, controlled trip out speed based on field experience, and proper core handling/ on-site core preservation was employed. The innovative approach resulted in achieving a recovery factor of more than 93 percent of high quality cores.
Benefits of Real Time Pressure Monitoring from Surface Read out Devices Case History- Zino Hub
Authors: Linda Dennar , Monday Nanpan , Olatubosun Aderibigbe , Chima Emelle , Onyinyechi Ekerendu , Uwem Essien , Amaraizu Odoemelam , John Oboh , Martins Amos
Published: October 2018

The Zino Hub is a very active gas hub within the Niger Delta region responsible for the delivery of major gas production and growth projects for key customers both in the export gas domain and IPP space. There are 38 producing gas wells completed across 19 reservoirs within this hub. These wells are pivotal to the delivery of gas to ensure the daily contractual agreements allotted to the hub is met. Due to the prolific and high level of gas deliverability within the hub, the Well, Reservoir and Facility Management Plan (WRFM) is highly prioritized, rigorously challenged and implemented.

As a part of the regulatory and WRFM fix the basics requirement, these reservoirs are monitored regularly to ensure they are produced under very healthy and acceptable reservoir practices. Yearly budget allocations for surveillance drives the quality and quantity of data acquired over these reservoirs. Over the years, the major source of pressure acquisition from these wells have been via gauges deployed through wireline. This of course has inherent challenges spanning from human resource deployment to acquisition sites in the face of current danger of kidnaps, high logistics cost and man power shortage, well site accessibility, unforeseen danger associated with well entries, inability to acquire data concurrently on demand without jeopardizing production (deferments) and many other threats such as escalated costs ensuing from community restiveness and demands

Recently, there has been a gradual shift from the wireline pressure acquisitions to the deployment of Permanent Down Hole Gauges with surface read out facilities for some of these wells. The value and convenience vis a vis the wireline deployment can never be over emphasized. On the front line is the cost reduction achieved in surveillance cost via these PDHG deployment. The interface feeders deliver well and reservoir data directly from the wells to the office there by facilitating insitu monitoring of reservoir and well parameters and very quick analysis are done to ensure healthy production of these wells within their operating envelopes. Well performance and diagnosis are done often on demand because consistent data is available daily.

The benefits accruing from this deployment is transparently contributing to a more robust, accurate and readily available data to the engineers and end users. This paper will highlight the obvious benefits of this deployment and, also recommend future improvements that would facilitate better analytical result.
Reducing Uncertainties in Mud-Gas Data Acquisition While Drilling-Offshore Depo-Belt, Niger Delta
Authors: Onyeji J. A. , Ekanem A. U. , Owoyemi A. , Adole S. A. , Ekun O. A. , Nwankwo C. N.
Published: October 2018

Over the years, the acquisition of gas in mud is crucial to the exploration and production (E&P) industry for the evaluation of hydrocarbons presence in the geological formation, and for monitoring of drilling operations. The mudloging technique involves continuous gas extraction and analysis from a circulating drilling fluid for quantity and composition using surface gas trap, gas lines and gas analyzer. This paper presents major uncertainties that associated with gas acquisition during drilling, sources of the uncertainties, and the way forward to acquire highly accurate gas-in-mud data.

During the process of acquiring gas-in-mud data, some uncertainties have been observed which can adversely impact real-time decision making as well as cascading effect on the geological models built with this data. In some of the recent wells drilled in offshore depo-belt of Niger delta the following uncertainties were observed; (1) Shift-in-the gas analysis window- Methane (C1) and heavy gas components (C4 and C5) were present in the absence of some light gas components (C2 and C3), (2) Misaligned gas data- gas values acquired misaligned with the resistivity readings of the reservoir being drilled, and (3) Gas in mud (volume and component) underestimation across the reservoirs; Lao-2 reservoir up to 35 units (0.7%) total gas, and gas composition- C1 to C3, and Mao-1 reservoir up to 27 units (0.54%) total gas, and gas composition- C1 to C2 were recoreded at well 43H drilled. This study showed that these uncertainties could result from a drop-in sample pressure or moisture in the gas line, real-time transmission of gas in mud data in bit depth instead of lagged depth and poor calibrations of gas analyzer. The issues then, are how to minimize these uncertainties to obtain accurate gas in mud that truly represent the reservoir being drilled. A systematic approach was deployed to minimize the abovementioned uncertainties. The methodology adopted significantly improved the data acquired in the new well drilled in the field. Highly accurate gas in mud data were obtained in the same reservoirs at the new well (44H) across Lao-2 reservoir: 190 units (3.8%) total gas, and gas composition- C1 to C4, and Mao-1 reservoir: 430 units (8,6%) total gas, and gas composition- C1 to C5. The new well is about 200m away from well 43H. The new well 44H was drilled under same drilling conditions as well 43H; same drilling fluid properties, rheology, mud weight, bottom hole assembly configuration and within the same fault block. Thus, we recommend; constant inspection of surface gas trap and gas agitator, periodic blow back of gas lines, multiple points gas calibrations, detailed gas analyzer calibrations for both total hydrocarbon analyzer and gas chromatograph prior to drilling operations, Maximum of five percent standard error margin, and periodic inspection of gas analyzer filament.
Successful High-Angle Through-Tubing Cement Packer Deployment and Reperforation Using Coiled Tubing: Offshore Niger Delta
Authors: Osaronwaji Emmanuel , Nnajiofor Okwouma , Chemmarikattil Rohan , Talabi Olufemi , Onuh Haruna , Onobrakpor Ochuko , Omodu Orji
Published: October 2018

Most economically feasible production optimization plans for brown fields include deploying rigless technologies for accessing reserves originally considered marginal and were, therefore, bypassed during the early stages of field development. Because these bypassed reserves were not considered significant, most of the wells were completed leaving behind potentials above the production packer that were not considered economically recoverable. Within the Niger Delta mature fields, a greater percentage of the remaining recoverable reserves have been overlooked as bypassed hydrocarbon volumes. Redeveloping the bypassed pay in highly deviated high-angle wells presents challenges, and accessing them usually necessitates pulling the tubing through a major rig workover. Such operations use far greater resources than rigless well interventions offshore and can often consume unaccounted for time in milling.

Rigless through-tubing cement packer technology and reperforations have been deployed to access marginal/bypassed pay in mature fields. Cement packers typically provide a means of zonal isolation of the last reserves in an existing wellbore above the production packer. The success of these operations has historically been low in highly deviated wells primarily because of poor cement bonding in the annulus between the tubing and production casing and issues with pulling the coiled tubing (CT) out of hole while maintaining differential pressure between the wellhead and casing head pressures.

This paper presents the successful deployment of through-tubing cement packer rigless reperforation without sand exclusion for accessing bypassed hydrocarbons in high-angle (72 to 80°) deviated wells through CT, offshore Niger Delta. This paper reviews design considerations and precautions for placing the high-angle cement packer through CT as well as production results. Post-operation shut-in tubing and casing pressure, quantity of cement slurry pumped, and extended flow testing have proven the success of the design and procedure implemented.
Annular Packer Seal Remediation through the SS in a Dual Completion Using Coiled Tubing: Onshore Niger Delta
Authors: Atakele Longfellow O. , Anim Osadebe J. , Airhis Osahon N. , Omodu Orji , Onobrakpor Ochuko , Onuh Haruna , Udensi Anthonia
Published: October 2018

A dual string well in the Northern Niger Delta was diagnosed with a well integrity problem resulting from mechanical setting failure of the long string (LS) packer during initial completion. The well was designed to produce the deeper condensate reservoir through the LS and shallower black oil through the short string (SS). The packer failure created wellbore communication across the two strings, which resulted in the shutting in of the well because of a sudden increase in water cut. The communication was evident in the condensate production from both strings, suggesting production loss from the deeper condensate reservoir to the shallower black oil reservoir.

A cost effective solution without recompletion was necessary to isolate the leak across the packer and eliminate the cross string communication. The initial proposal was to perform a rigless through-tubing operation that would involve setting plugs in the LS and perforating the LS to enable setting of the cement plug on the failed packer. The downside to this approach is difficulty milling the cement and plugs in the tubing after the operation, as well as the complexity of the entire operation.

This paper presents a novel solution to the problem by deploying coiled tubing (CT) with optimized cement slurry through the SS. Six CT runs were made, exiting the SS 1,365 ft in each run and thereby eliminating the cost of plugs and perforation in the LS. The pump and pull method was used to spot the cement plug. The packer leak was isolated, and black oil production was established through the SS. Postoperation production proved the design a success. The procedure was implemented resulting in more than a 60% increase in production from both strings, and water cut was reduced to less than 1%. A cost reduction of more than 90% was realized compared to a workover option.
Economic Viability of Infil Drilling Program for Marginal Oil Field Development: A Case Study of Sango Field in Nigeria
Authors: Dagogo Opiribo , Iledare Wumi , Humphrey Oruwari
Published: October 2018

Infill drilling can be defined as the drilling of an additional well in a field that has already completed primary production; it is a rate acceleration investment that increases cash flow schedule similar to installing large volume lift equipment. The study evaluates the economic viability of applying infill drilling program to marginal oil field development in Nigeria using Sango field as a case study. This study was carried out to evaluate the economic viability of infill drilling program for marginal oil field development in Nigeria using Sango Field as case study. The study employs the dynamic reservoir simulation using Eclipse 100 Black oil simulation software to quantify the infill potential of the remaining reserves and based on the results of the incremental recovery from the simulation, one additional well was proposed for drilling. Economic analysis was carried out on the drilling prospects using cash flow model to evaluate the profitability. Stochastic evaluation of the deterministic single values was conducted using Oracle Crystal Ball software to quantify the risk and inherent uncertainties. This was followed by performing a sensitivity analysis to determine the effect of key variables on the profitability of the venture. The result of the analysis showed that the Long Term Activities (combined) scenario recorded the highest incremental recovery of 2.45MMSTB. The project Net Present Value for the drilling option is $1.0 Million at a discount rate of 11% while the internal Rate of Return is 12%, the profitability index is 1.1 and Payout Period of 4.26 years. Probabilistic analysis gave better confident level that encourages investment while the sensitivity analysis revealed tax rate, oil price and initial investment as key parameters affecting the profitability of the venture. The long time activities that gave an incremental of 2,45MMSTB was proposed for the Sango field which involves the production of the fields with both old existing well and the newly drilled well. It is recommended that there is the need for less demanding and cost effective method to quantify infill potential in marginal oil field as against the detailed integrated reservoir study that is time consuming and expensive for operations of marginal fields. The significance of the study is that it will provide valued information for marginal field operators that will guide investment decision making.
Upstream Mergers and Acquisition Deal Valuation - A Global and Africa Outlook with Perspectives for Nigeria
Authors: Gbakon Kaase , Abiola Olalekan
Published: October 2018

The objective of this paper is cast as a historical narrative of the global oil and gas upstream M&A activity as revealed by such metrics as deal count, deal value, quantum of proved reserves up for M&A and the accompanying segregation by region, deal category, and terrain location of deal asset. Furthermore, the study contemplates the question on the character of the next cycle of M&A activities within the Nigerian upstream space. Additionally, the paper explores the possibility of adjusting valuation methodologies based on the result obtained.

For this assessment, the paper relies on a database of M&A transactions which contains 6,444 deals from 2001 to 2017 (Sept.). The database is queried for deals for which there is a reported deal value thus allowing M&A deal activity to be tracked, trended, and correlated. This provides a critical look back on the dynamics of the M&A market with a view to offer an outlook of the M&A deal space. Approximately 77% of the parent database size contain transactions with deal value recorded. Both the annual M&A deal count, and the deal value closely track the trend for oil price with correlation coefficients of 76.34% and 65.84% respectively. Over seventeen years from 2001, an estimated $2.22Trillion (RT2016) of M&A value has been transacted, 56% of which has been due to transactions primarily in North America, 17% in Russia and the Caspian, 8% in Europe and 5% in Africa.

Segregating deal value by asset location reveals a constrast between deepwater and onshore. In terms of value, DEEPWATER acquisitions totaled $230Billion (RT2016) globally over the 17year period, which is only 15% that of ONSHORE acquisitions while the aggregate unit deal value for DEEPWATER at $19.50/BOE (RT2016) is more than 2–times that of ONSHORE acquisitions. Within the Africa M&A deal space, data shows that deal value is driven primarily by oil price and proved Serve Size (in MMBOE), with the greater impact due to the Proved Reserve size in the target deal where a 10% change each in Reserve size and Oil Price results in 10.74% and 8.53% change in deal value respectively. To further the study, a closer look at the Nigeria M&A space was undertaken.
A New Approach to Maximum Efficiency Rate Estimation in the Niger Delta
Authors: Sukubo Ibianga , Obi Peter
Published: October 2018

Maximum efficiency rate (MER) is the production rate above which the reservoir recovery (particularly around the well) is endangered thereby eroding lifecycle economic value. The current practice in the Niger Delta entails the application of the equilibrium concept which (in this case) requires the use of a combined graph of tubing head pressure (THP) and choke size against the production rate where the point of intersection between the plots is considered the stable equilibrium and the corresponding rate, the MER. However, experience has overtime shown that adjustment of the scale of the vertical axis would yield different values of MER; and thus can be adjudged as physically inconsistent.

To address this inconsistency, a robust methodology that will be acceptable to both the regulators and partners is being proposed by first understanding and establishing the limitation of the current methodology and demonstrating same using the combined THP and choke size versus production rate plots on a single graph. Subsequently, the relationship between key elements of changing THP (due to varying choke sizes) and their attendant back-pressure effect at the sand face impacting on reservoir withdrawal at given physical well conditions was established and normalized (using first order derivative function) to capture possible variations in the tubing head and sandface pressures over any production period.

The impact of choke size adjustment on the ‘changes’ in THP and production rate at a particular physical well condition was modeled and a combined plot of the ‘change’ in THP and production rate at varying choke sizes was then generated on a single graph. The result proves to be more physically consistent and can easily be replicated across the industry.

This paper demonstrates the gap in current MER estimation methodology and proposes a new thinking and more effective approach; sharing the results of its application and value for both regulators and operators.
Unconventional Challenges and Solutions in Liner Cementing: A Case History from Nigeria
Authors: Adesanya Olukayode , Mofunlewi Samuel S. , Ighodaro Osaze , Fagbemi Timothy , Ibrahim Timothy , Timibitei Fred
Published: October 2018

Incorporation of innovative well delivery practices has been on an increase over the years and there are several phases of operational engagement that aid in achieving the required well objectives. Primary cementing is a key phase of wellbore construction as it secures the well's structural integrity, also serving as a barrier to keep formation fluids at bay.

There are several challenges associated with carrying out wellbore zonal isolation for conventional primary cementing of casings. However, a unique level of attention is required during the design and execution stages of liner cementing. The slurry design requires careful formulation to desired specifications while ensuring it is easily deployed and placed in the liner annulus. Additionally, there are several downhole tool constraints that come with liner cementing related to the complexity of the liner hanger technology. Various tool configurations are available to make up the liner hanger system. A typical system will include casing joints and the liner top packer Run in Hole (RIH) to the designed depth.

The process of cementing a liner comes with unique procedures. From the design phase to the execution, special consideration of all downhole fluids to ensure flawless cement placement while preventing intermixing and contamination is critical. The complex nature of the liner hanger system requires thorough analysis in order to provide lasting solution to effectively perform cementing placement and zonal isolation throughout the liner casing, hanger assembly and liner top.

One major challenge is the risk of possible contamination of the cement slurry with un-displaced mud in certain sections of the liner hanger system. The effects of mud/cement contamination can lead to grievous consequences and is fully analyzed in this paper. A high profile cementing operation carried out in the southern part of Nigeria is used as a case study on how the liner hanger configuration and drilling fluids design can positively influence the successful deployment and effective zonal isolation of the liner. Emphasis on several procedural considerations that are often overlooked while designing the drilling fluids properties and characteristics for liner hanger cementing will be presented with recommendations on tracking and with improvements in future operations noted.
Quantifying the Impact of Water and Gas on Oil Production
Authors: Egba Amba Ndoma , Ajienka Joseph A. , Iledare Omowumi O.
Published: October 2018

The impact of water, gas or a combination of both in oil production is an important aspect of petroleum engineering operations. Some water or gas production could contribute to oil production increase while in some cases such production could be less beneficial. Analytical techniques to quantify the impact are still lacking because the solution to multiphase flow problems in heterogeneous reservoirs is complex. Material balance procedures are deterministic and do not take into account the heterogeneity in reservoir behavior. Simulation techniques could be used but these are very expensive and require, a lot of time and information, which may not be handy.

Using time series data analytics techniques, a method has been developed that is used to quantify the impact water, gas or a combination of both will have on oil production, in the short run and in the long run. This technique is also used to determine whether water, gas or a combination of both is a significant causal factor in oil recovery or not. The approach is innovative as it will help to isolate desirable and undesirable water or gas production before applying expensive diagnostics.

This new Method has been tested with field data and could be a useful tool for reservoir and production engineers.
Application of Fluid Contact Match in Material Balance Study in a Water Injection Reservoir to Estimate STOOIP and Initial Reservoir Contacts
Authors: Obot Nsitie , Eme Vincent
Published: October 2018

Original hydrocarbon in-place and aquifer influx for a reservoir can be estimated using the classical Material Balance Equation (F = N*Et + We). Being a single equation with many unknowns, this makes the solution to the equation non-unique with a wide range of OHCIP estimates. Including fluid contact tracking helps to constrain the range of OHCIP and better define the initial conditions of the reservoir.

The objective of the material balance study was to estimate the STOOIP and initial reservoir fluid contacts for two waterflooded reservoirs. The volumetric estimates of STOOIP for the proved area (defined by the HKO and ODT) gave very optimistic recovery factors to date. This paper will discuss the methodology used for estimating the initial reservoir condition by using fluid contacts tracking to constrain the material balance equation for production history match.

Reservoir A2 was discovered with no initial fluid contacts seen in the reservoir prior to the onset of production. Water injection started in the reservoir after fourteen years of production. Oil RF to date from the reservoir is over 61% of the volumetric STOOIP estimate (265 MMSTBO) using the first fluid contacts seen in the reservoir post-production.

Reservoir A3 was discovered with an OOWC and HKO with volumetric STOOIP estimate of 295 MMSTBO. Initial water injection started in the reservoir after fourteen years of production. Oil RF to date from the reservoir is 71%.

Integrating fluid contacts tracking in the material balance study helped constrain the STOOIP estimates and give more realistic values (45 – 50% for reservoir A2 and 60 – 65% for A3). The STOOIP and initial contact estimates from this study were used as basis for comparison with the dynamic simulation study and the results were within 5%. These case studies show that applying fluid contact matching in material balance can help with better estimates of STOOIP and initial reservoir fluid contacts.

This is of great importance to the optimum development of these reservoirs and has led to the identification of new drill opportunities in each reservoir.
Phytoremediation of Petroleum Hydrocarbons in Polluted Waters Using Pistia Stratiotes: Gaps and Future Perspective
Authors: Ekperusi Abraham O. , Sikoki Francis D. , Nwachukwu Eunice O.
Published: October 2018

Environmental pollution in the oil and gas industry is the unintended but inevitable consequences of oil and gas exploration and production. Over the years, different strategies have been implemented for the remediation of oil-polluted waters. The increasing call for the use of ecologically based solutions for remediation have intensified the quest for engineers, researchers and scientists to find pragmatic solutions from the natural world. Among the several biological application for the remediation of petroleum-polluted environment, aquatic macrophytes are becoming a promising and ecological based solution for the removal of hydrocarbons pollutants in water. Pistia stratiotes, - a monotypic genus in the family Araceae, is a floating aquatic macrophyte with extensive application in the phytoremediation of organic pollutants, heavy metals and sparingly in agrochemicals, pharmaceuticals and personal care products, nanomaterials, radioactive materials and petroleum hydrocarbons in wastewater effluents and aquatic environment. The dearth of studies on the application of water lettuce for the remediation of petroleum hydrocarbons and oilfield chemicals creates a gap in the potentials of the plant for long and short-term assessment of hydrocarbon uptake, removal and degradation in contaminated waters. There is need for laboratory and field trials on the application of P. stratiotes to remediate hydrocarbons and other related pollutants in oil and gas exploration to elucidate the effectiveness and efficiency of the plant as a sound ecological base approach for sustainable remediation of hydrocarbons in a polluted environment.
Extended-Reach Drilling To Maximize Recovery From a Mature Asset: A Case Study
Authors: Muecke N.. , Wroth A.. , Zharkeshov S.. , Anton R.. , McCourt I.. , Armstrong N..
Published: October 2018

This paper shows how the implementation of a continuous-improvement process, in combination with precampaign-engineering and planning-optimization efforts, allowed the operator to expand the existing drilling-and-completion envelope in a mature offshore field. This provided a cost-effective means to access the remaining attic and undrained oil in a very shallow reservoir. Application of new technology, extended-reach-drilling (ERD) practices, complex completions, detailed engineering, good-quality real-time data, and execution support at the rigsite drove the evolution of well designs for the operator during the last 8 years, enabling the life of this mature asset to be extended. This paper highlights the evolutionary process applied to enable economic in-field development, with an emphasis on relevant transferable learnings that might be applicable to other complex ERD-well projects within the industry.
Application of Ultrasonic Waves in Enhancing Oil Recovery in Secondary Recovery Phase
Authors: Abdulfatah Hajara Kabeer
Published: October 2018

Recoverable oil may often remain trapped after secondary recovery processes due to capillary forces, inapt mobility ratio & heterogeneity in the reservoir. To optimize oil recovery, more oil has to be mobilized using enhanced oil recovery (EOR) techniques that are not always so economical. Use of ultrasonic stimulation in the reservoir is a recent innovation that is scarce in literature. It is less risky and it helps to overcome interfacial tension between oil & water, reduce capillary pressure & aid oil mobilization.

This paper presents the use of ultrasonic waves in enhancing oil recovery in the tertiary recovery phase using Niger Delta crude oil. Laboratory experiments were carried out and a 3D model of a reservoir created using the Schlumberger eclipse 2010 simulator to predict the performance of the base (water flooding) was employed. The experimental work was in two folds termed test A and B. The former was performed without ultrasound while the latter involves the use of ultrasound (up to a frequency of 54kHz) in the designed flooding system. The resulting relative permeability data from both approaches were obtained and comparatively analyzed.

Using MATLAB, results showed that the use of ultrasound waves in reservoirs (permeability> 20 mD, porosity > 15%) leads to increase in recovery by up to 50%. This increase is due to the ability of the waves to unblock the pores, thus creating larger path for the reservoir fluid to flow. The flooding scheme shows that the use of ultrasonic waves in the porous medium yielded a reduction in the critical oil saturation of 0.09 which represents 25.4% of the residual oil saturation obtained with water flooding scheme. Critical oil saturation values of 0.28 and 0.37 were obtained for the wave stimulation and water flooding schemes respectively. The results also shows connate water saturation of 0.27 at relative permeability to oil of 1 which is typical of the results from a well performed imbibition process.
Seismic Onset Time Inversion Method for Infrequent Seismic Surveys
Authors: Liu Tian
Published: October 2018

The integration of seismic data into high-resolution geological model, provides great potential for calibrating reservoir parameters, which enables better understanding of the reservoir sweep and flow patterns. The efficacy of seismic inversion method based on the travel time of fluid saturation front using seismic onset times has been well demonstrated for integrating frequent time-lapse seismic surveys. However, due to the high cost associated with conducting seismic surveys, frequent seismic surveys are usually not commonly available. In this paper, I have generalized the onset time inversion method for infrequent seismic data using interpolated seismic onset times, making the method applicable for efficiently integrating infrequent seismic surveys. With the valuable information provided by seismic data, the uncertainty in the reservoir model parameters can be reduced through history matching. The history matched model can be used to optimize reservoir management and field development strategy. The proposed method is illustrated using synthetic and field applications.
Pore Pressure Prediction in Unconventional Carbonate Reservoir
Authors: Elmahdy M. , Farag A. E. , Tarabees E. , Bakr A.
Published: October 2018

Prediction of the formation pore pressure is considered as a significant simulation process during the drilling and production phases of the carbonate reservoir. The deficiency in this prediction allows for the occurrence of many troubles like blowouts, kicks, hole washouts, wellbore breakout, and stuck pipe. The most common conventional methods for the pore pressure prediction are Eaton's and Bower's methods which depend mainly on the normal compaction trend and commonly applied on Shales. The objective of this work is the prediction of the formation pore pressure by the application of the modified Atashbari prediction model upon the wireline logging data. This method depend on the porosity and the compressibility attribute of the rocks for the estimation of the pore pressure without any need for the normal compaction trends. The method was applied on the carbonate reservoir of the Middle Eocene Apollonia Formation, Abu El-Gharadig basin, Egypt. It is a gas bearing reservoir which characterized by its high porosity and low permeability. The results were compared with the other commonly used methods and show an improvement in the pore pressure estimation. It can be used as an individual method or in complement with other available methods.
Anais 1º COREO - Congresso Internacional de Reabilitação Oral
Authors: Menezes Diogo José Barreto de , Galvão Anna Karyna , Ribeiro Eduardo Dias , Franceschini Neto Francisco , Lima Júnior Marcos Aurélio Vasconcelos , Silva de Matos Robert , Freire Julliana Cariry Palhano , Pereira Laudenice de Lucena , Viana Filho José Maria Chagas , Gonçalves Patrícia Guerra Peixe , Pinheiro Rachel Christina de Queiroz , Rodrigues Raíres Chaves da Silva , Santos Carllus Alberto Oliveira dos , Nóbrega Sheyla Christinne Lira da , Abílio Vanessa Maria Freire , Lima Larissa Chaves Morais de , Suassuna Thalles Moreira , Oliveira Elson Tadeu Fernandes de , Caldas Aparecida Tharlla Leite de , Souza Ricardo Liberalino Ferreira de , Santos Fábio Gomes dos , Figueiredo Viviane Maria Gonçalves de , Campos Fernanda
Published: October 2018

Prezados Colegas,         É com imensa satisfação que convido a comunidade odontológica para participar do I Congresso Internacional de Reabilitação Oral - COREO, a ser realizado no Centro de Convenções de João Pessoa, nos dias 27, 28 e 29 de setembro de 2018.  O COREO surgiu da necessidade de trazer para a região nordeste uma agenda científica em odontologia, com foco voltado para a reabilitação oral, priorizando a prática clínica baseada em evidências científicas.          O tema central do I COREO será “Mudança de paradigma com relação às novas tecnologias”. Baseado nessa temática, serão discutidos nesse evento, as novas condutas e protocolos clínicos e científicos com o objetivo de usufruir dos novos recursos tecnológicos disponíveis nas diversas especialidades, na busca de tratamentos mais previsíveis em longo prazo. Para abrilhantar o evento, selecionamos conceituados conferencistas com expressivo conhecimento científico, aliado a experiência clínica.       Aproveitando o ensejo, reiteramos o nosso convite aos colegas Cirurgiões-Dentistas, Acadêmicos de Odontologia, Técnicos em Prótese Dentária, Auxiliares e Técnicos em Saúde Bucal para fazer um grande e inesquecível evento, que ficará para a história da Odontologia Brasileira.Diogo José Barreto de Menezes - Presidente do 1º COREO
Emergence of High-level Gentamicin Resistance among Enterococci Clinical Isolates from Burn Patients in South-west of Iran: Vancomycin Still Working
Authors: LABIBZADEH MARYAM , KAYDANI GHOLAM ABBAS , SAVARI MOHAMMAD , EKRAMI ALIREZA
Published: October 2018

Enterococcus faecalis and Enterococcus faecium are among the main agents associated with nosocomial infections with high mortality in immunocompromised patients. Antibiotic resistance, especially against gentamicin and vancomycin among Enterococci, is a risk factor that could increase the morbidity and mortality rate. 179 Enterococci isolates from burn patients were included in this study. Antibiotic susceptibility testing was done using the disk diffusion test and minimum inhibitory concentration (MIC) was evaluated by agar microdilution. Vancomycin and gentamicin resistance associated genes including vanA, vanB, vanC, aac (6’)-Ie aph(2’’), aph(3’)-IIIa and ant(4’)-Ia were detected by PCR and their statistical relation with antibiotic resistance was evaluated. E. faecalis was the more prevalent strain among our local isolates and showed a higher antibiotic resistance in comparison to E. faecium. Vancomycin had a good antibacterial effect on the Enterococcus spp. isolates; however, resistance to this antibiotic and a high-level gentamicin resistance (HLGR) phenotype were observed. Among van operon genes, vanA was the most prevalent gene and among the gentamicin resistance genes, aph (3’)-IIIa was more frequent. The HLGR Enterococci are a real challenge in nosocomial infections. Vancomycin is a key antibiotic to treat such infections but emergence of VRE in our region could be a real concern and, therefore, phenotypic and molecular surveillance must be considered.
The Use of Pomalidomide in the Treatment of Relapsed/Refractory Multiple Myeloma in Patients with Renal Failure
Authors: Rekhtina Irina Germanovna , Nareiko M.V. , Mendeleeva L.P.
Published: October 2018

The present review includes data on efficacy and safety of pomalidomide, an immunomodulating 3rd generation drug used for treatment of relapsed and refractory multiple myeloma patients with renal failure. The results of multicenter randomized trials proved similar efficacy and comparable safety profile in patients with normal renal function and patients with moderate and/or severe renal failure. All patients received the standard starting dose. Pomalidomide dose needs to be reduced in response to hematological toxicity. The paper provides practical guidelines on the use of pomalidomide and treatment of adverse events adopted by consensus of international experts. Current approaches to multiple myeloma with renal failure, and the use of pomalidomide in particular, are demonstrated by means of a clinical case.
Erythrodermic Mycosis Fungoides: The Algorithm of Diagnosis and Treatment
Authors: Olisova O.Yu. , Sydikov A.A. , Chuprov I.N. , Gorenkova L.G. , Chernysh S.A. , Doronin V.A. , Grekova Ekaterina Vladimirovna
Published: October 2018

Erythrodermic mycosis fungoides (eMF) is an atypical severe form of mycosis fungoides resulting from persistent and treatment-resistant disease. eMF manifests as generalized skin bluish lesions, intense itching, secondary lymph-adenopathy, and significant deterioration of quality of life. A differential diagnostic algorithm for various forms of eryth-rodermia is suggested. The paper presents a clinical case of eMF with spots and plaques that skipped the tumor stage. Experience of eMF treatment using vorinostat, gemcitabine, doxorubicin, and alemtuzumab is described.
Immune Checkpoint Inhibitors in the Treatment of Lymphomas
Authors: Lepik Kirill Viktorovich
Published: October 2018

Programmed death receptors and ligands (PD-1 and PD-L1) are the best studied immune checkpoints (ICP) and are considered to be key factors of immune response control. The ability of tumor cells to affect the ICP receptors is one of the principal mechanisms of suppressing antitumor immunity. The development of ICP inhibitors creates an opportunity to control and activate immune response and opens new perspectives for immunotherapy of cancers, including lymphomas. The paper reviews the biological background for the use of ICP inhibitors in the treatment of classical Hodgkin’s and non-Hodgkin’s lymphomas and summarizes the clinical experience of their use. The new approaches for the creation of combination regimens with ICP are also highlighted.
Immunological Synapse in the Biology of Chronic Lymphocytic Leukemia
Authors: Badmazhapova Darima Semunkoevna , Gal'tseva I.V. , Zvonkov E.E.
Published: October 2018

Chronic lymphocytic leukemia (CLL) is a lymphoprolifera-tive disease manifested by accumulation of tumor B-cells with characteristic immunophenotype (CD19+CD5+CD23+) in bone marrow, peripheral blood and secondary lymphoid organs. The clinical course of CLL is heterogeneous. This is the most prevalent leukemia among older-aged patients. Despite the use of novel drugs refractory forms of disease remain. The latest discoveries in immunology enabled understanding of some mechanisms of tumor evasion from immune surveillance. The interaction of immune system cells occurs due to the development of immunological synapse that predominantly depends on the family of CD28/В7 molecules, the so-called immune checkpoints able to control the activating and inhibiting mechanisms of cells. The acquisition of tumor phenotype is a multistage process, in which cells obtain unique biological properties including the ability of being invisible to the immune system. As opposed to solid tumors in lymphoproliferative diseases tumor B-cells are able to express major histocompatibility complex class II and CD80 and CD86 co-stimulatory molecules. It proves their ability to present antigens to T-cells. Co-inhibitory molecules on the surface of tumor cells is a factor contributing to the inhibition of immune response. The present paper reviews current conceptions of biological properties and immunological interactions of CLL cells with the microenvironmental cells.