bluuebunny/crossref_metadata_2025 huggingface dataset:
Well Services Operations in Offshore Unmanned Platform; Challenges and Solutions
Authors: Alyafei Othman
Published: March 2015

INTRODUCTION

Successfully performing well interventions safely, on-time, and within budget on unmanned offshore installations poses a unique set of challenges to overcome. The conditions regarding unmanned offshore installations are more restrictive than with other types of facilities, and each campaign of well services activities introduces new complexity and requirements. Three main factors affecting performance are focused on: personnel accommodation, safety systems, and weather. The limitations, lessons learned, and resulting improvements implemented from each campaign are enumerated and discussed. Additionally, some mitigating measures implemented to limit the impact from the three factors are presented.

Various strategies were employed to mitigate negative impact on campaign safety, cost, and schedule. Some challenges include how to address personnel accommodation and equipment limitations (number, size, and weight) through the use of supply vessels, DPI/DPII intervention vessels, jack-up rig, fast crew transfer, barge, and Liftboat. Another area that required numerous remedial measures was safety systems, e.g. fire water/deluge systems. Other conditions that affect performance are the reservoir's relatively shallow nature and down-hole conditions that require special rig-up. Along with scope of work challenges, weather is a major consideration when determining the intervention strategy for unmanned platforms. Determining how to limit standby time, overcome personnel and equipment limitations, and continue to work safely is the greatest challenge of all. All of these requirements formulate part of the criteria in selecting an intervention vessel/rig/Liftboat which directly impacts schedule and cost.

The major challenges over the past few years will be discussed, including their effectiveness, efficiency, and specification. Furthermore, a summary of how the challenges were overcome based on safety, uptime, and personnel accommodation is given.
Economics of Power Production from Forward Osmosis
Authors: Jacob Matthieu , Garnier Olivier Francois , Lebas Genevieve
Published: March 2015

Forward osmosis (FO) uses an osmostic pressure gradient to induce a net flow of water from the solution feed (low salt concentration solution) into the draw solution (higher salt concentration solution) through a semi-permeable membrane. The osmotic pressure can then be converted into a hydraulic pressure used to run a Pelton turbine and to produce green electricity. The permeate flow is then always kept at high pressure (15–30 bars) to feed the turbine using a pressure exchanger; this technology is called Pressure Retarded Osmosis (PRO). Oil terminals are rejecting to sea large quantities of salty produced water (above 100 g/l) and there is a potential for the application of PRO using this produced water as the draw solution and the sea water, river or lagoon water as the low-salt feed solution. Forward osmosis between sea water and production water could be used to produce electricity with low additional environmental impact. A technico-economical study was launched to evaluate the potential interest of PRO technology to produce electricity on the Djeno oil terminal site situated in Congo. The calculated technical cost of electricity is from 350 to 650 euros/Mwhr, which is not competitive with other green energies. This high cost is mainly due to required bulk equipments and their related electrical consumption, the membrane cost being only 10% of the technical cost. So though the technology seems promising, a technical breakthrough on membrane permeability and mechanical resistance is needed to promote PRO as a competitive clean energy.

1.Generalities on forward osmosis

Osmosis is a natural phenomenon which occurs when a water-permeable membrane separates two solutions of unequal salinity. The pure water diffuses from the less concentrated to the more concentrated region. The energy of this motion can be captured and converted to green electricity. This process, firstly described by S.Loeb in the seventies [1–3], is usually referred as pressure retarded osmosis (PRO). Considering two fluids referenced as Feed solution (F) and Draw solution (D) of different salinity (and thus osmotic pressure) separated by a FO membrane, the water from the less saline compartment F will transfer through the FO membrane to dilute the more saline compartment D (equation 1 and equation 2). The compartment D flow is then canalized and divided into two streams, one going through a turbine to generate energy (equation 3) and the other going to a pressure exchanger where it increases the pressure of the saline (draw) solution (see Figure 1). PRO process requires a back pressure on the high salinity draw solution that generates power by depressurizing the solution through a turbine. To maintain a steady operation of the turbine, the permeate flow should always been kept at high pressure (15–35 barg) to feed the turbine. The water permeate flowrate (Jp) against the applied back pressure Pdraw depends on the osmotic pressure difference, which thereby converts the chemical potential energy into mechanical work.
Qatar Petroleum Experience in Implementing the Measurement Strategies for Custody Transfer, Allocation and Royalties.
Authors: Bolivar Carlos
Published: March 2015

From the reservoir to the final consumer sales point, the flow and quality related to energy is estimated, quantified, or in an ideal situation is measured with very low uncertainty. Organization of Petroleum Exporting Countries (OPEC) reference basket averaged $107.52/b in August, and the world oil demand growth was revised in 2013 by 25 tb/d (1), in the longer term, prices may reach $155/b by 2035 (2), additionally, energy consumption has been estimated to increase 54% from 2010 to 2035, fossil fuel will account with 82% (2). Considering these short and long term estimations, the proper management of the uncertainty levels related to measurement systems in the energy sector has an intrinsic financial risk exposure that has to be addressed, and in most of the cases, a clear framework has to be established and led by the reserves owners.

Technology has been evolving to manage better levels of uncertainty, but it is an endless journey trying to find the "true value" in order to safeguard the net profits of the shareholders. In the case of National Oil Companies (NOC), this challenge is translated in major strategic paths that are fully linked to the long term vision of an entire nation, and if we consider the nations where the Gross Domestic Product (GDP) is propelled by the Oil and Gas sector, the discrepancies related to product measurement may create a tremendous impact in the domestic economy. In consequence, around the supply chain, where different parties are directly involved in energy custody transfer process, the transparency and clear measurement terms are required for the buying and sales transactions. In many of those cases, royalties payment is involved, this issue must be fully monitored and controlled by the NOCs, but clear terms has to be agreed with the International Oil Companies (IOCs) in order avoid financial losses due to sub-optimal measurement practices.

Qatar Petroleum (QP) has embarked in an ambitious task to implement a "Measurement Strategy", to be applied to all the Joint Ventures and Production Sharing Agreements Operators that are located in the State of Qatar (SoQ). One of the key elements in the Measurement Strategy is the creation of a common framework to operate the measurement systems in the SoQ. The complexity lies to boost this initiative in an environment where different players have already an intrinsic risk related to their own operations in terms of hydrocarbon imbalances due to measurement uncertainties, and every single operator could operates the measurement system with a different asset management strategy. This paper will present the case and the lessons learned from this implementation process in order to deploy an unique framework to manage the measurement systems, where, the approach utilized to manage the diversity from the managerial perspective was based in the Kotter method.
Intelligent-Field Technologies on a Mass Scale: Change for Efficiency Improvement
Authors: Al-Khelaiwi Faisal T. , Zarea Marwan A. , Al-Khamis Mohammad N. , Al-Ghamdi AbdulRahman A. , Al-Amri Meshal A.
Published: March 2015

The Northern Area Oil Operations of Saudi Aramco has embarked on the installation of Intelligent Field equipment and innovative technologies on a mass scale for the past decade. It was noticed that the initial performance and utilization of such technologies were lower than expected. Therefore; a plan comprised of the following was devised to tackle these deficiencies:Launching a major organizational restructure and assigning a dedicated team of specialists to look after the Intelligent-Field equipment and the real-time data transmission to the databases.Establishing a tailored maintenance service contract with the providers of such technologies.Developing an in-house training program for specialization in the operation, maintenance and utilization of Intelligent-Field equipment.Launching of an innovative technology deployment and evaluation program where each technology is assigned to a technical champion who assumes full responsibility of the technology deployment process.Initiating and maintaining state-of-the-art knowledge management system to track the progress, document the procedures and processes, and capture the lessons learned from the application of each technology.

The implementation of these steps resulted in enhanced Intelligent-Field equipment performance efficiency. In addition, the utilization of real-time data — in advanced production and reservoir engineering analysis; such as automated well rate validation and allocation, production optimization and sweep monitoring — has improved due to the high availability and quality of the transmitted data.

This paper will provide details of the holistic approach developed by Saudi Aramco for the installation and maintenance of Intelligent-Field equipment and all the implemented changes in the work processes to maximize their performance and tangible benefits. The success and value-added by implementing this generic approach will be illustrated through the high efficiency of Saudi Aramco's Intelligent-Field equipment, which has been maintained at 99%.
An Adapted Uncertainty Management Methodology and Tool for Fast-Track Approaches: Light-Up
Authors: AHN S. , SCHIRMER P. , TAWILE E.
Published: March 2015

The global workflow of Light-Up

Light-Up (for Light Uncertainty Process) is part of TOTAL's in-house tools for uncertainty management. Light-Up provides (1) the assessment of the probabilized HIIP distribution and (2) the methodology and tool to build "tailor-made" models that feed fluid flow simulation for reserves evaluation with or without dynamic uncertainties. Because the uncertainty workflow of Light-Up is pragmatic and fast, Light-Up has been used for several years on a large panel of TOTAL operational cases. The uncertainty workflow which includes Light-Up, composed of 4 main steps, constitutes an integrated workflow.

1. BASIC DATA

Firstly, the selection of the Base Case geomodel is performed through an in-house non-ergodicity diagnosis. Once uncertainty ranges of static parameters (such as fluid contact, structure, facies proportions, geobody extension and petrophysics) are defined, mono-sensitivity runs are conducted and HIIP is computed for each run. A Tornado Chart is then built to rank the uncertainty level of key parameters on HIIP.

2. STATIC ASPECT

Then, an innovative in-house formula combined with Monte Carlo runs within the Tornado Chart allows computing the probabilized HIIP distribution with the determination of Q10, Q50 and Q90 volumes as well as its dispersion.

3. DYNAMIC ASPECT

Secondarily, because dynamic uncertainties studies for reserves and resources estimation (lead by EST) need to be fed with alternative models (called "tailor-made" models), Light-Up provides a robust methodology and tools (called the Quantile Extraction method) to build these models. This method lies on the uncertainty level control of each uncertain parameter with a weighted variations of parameter quantiles.

4. DETERMINISTIC MODELS

Finally, following the dynamic uncertainties assessment, the Quantile Extraction process of Light-Up allows the construction of deterministic static geomodels which have Low, Best and High dynamic responses for a given dynamic setup (Low, Best and High dynamic setups).
Innovative Integrated Process Scheme For Native CO2 Recovery
Authors: Weiss C. , Pousse F. , Ghodasara K. , Linicus M. , Jüngst E. , Fränkel Stefan
Published: March 2015

While considering CO2 emission from a gas plant, native CO2 significantly contributes to the total amount. Capturing this native CO2 can reduce a lot the green house gases emission and captured CO2 can be valorized for Enhanced Oil Recovery. Due to this, Oil and Gas operators are more and more interested in improving native CO2 recovery technologies.

Usually when natural gas contains both CO2 and H2S, they are removed together and sent to Sulfur Recovery Unit resulting in a tail gas containing mainly Nitrogen and CO2. CO2 can then be separated by use of solvent (using MEA e.g.).

TOTAL and Air Liquide have developed and patented an innovative process scheme recovering native CO2 and reducing the operating and investment costs. Claus unit fed with pure oxygen instead of air leads to a tail gas stream, containing mainly CO2 and H2. Then, CO2 purification unit allows recovering a CO2 rich stream with purity even up to 99.9%. This purification unit can be either membrane, cryogenic or adsorption technologies, or a combination of them. This paper also discusses about the integration of Oxygen-based Claus technology (OxyClaus), tail gas treatment unit (TGTU) and CO2 purification.

The scheme has been studied in detail for specific application to optimize the overall integration. It has been also compared to conventional CO2 capture scheme to highlight its benefits leading to significantly lower CO2 recovery cost. This scheme contributes in many aspects to the current technical knowledge which may include low-cost CO2 capture, use of pure oxygen in the Claus, CO2 purification for EOR etc. Other benefits also include the size reduction of the Claus/TGTU, production of nitrogen stream to be valorized and separated H2-rich stream from CO2 purification unit.

This paper will comprise the overall scheme description and discuss some results for the specific case study.
Virtual Outcrop Geology - A Case Study on Effective Learning and Data Preservation
Authors: AhmadZamri Ahmad F. , Al-Mannai Ahmad S. , Strohmenger Christian J. , Foeken Jurgen P. T.
Published: March 2015

The use of a terrestrial laser scanner to capture outcrop information has grown in popularity in recent years as a complementary method to geological field work. Laser scanning technology provides a huge volume of geo-referenced data which can be integrated with other datasets. It not only allows 3-D visualisation of the scanned outcrops but also complex qualitative and quantitative analysis of outcrop information.

Light Detection and Ranging (LiDAR) technology was used as the basis for development of an interactive 3-D stereoscopic module of ancient outcrop analogs for Khuff Formation deposited in Eastern Arabian Peninsula. Seven of these outcrops, located in Wadi Bih and Wadi Hagil (Ras Al-Khaimah, U.A.E.) and representing carbonates of the Permo-Triassic Bih, and the Triassic Hagil and Ghail formations were captured using LiDAR technology.

In order to obtain the highest quality dataset for visualisation purposes, a terrestrial laser scanner with mounted calibrated digital camera was used to capture outcrop information. The outcrops show lateral and vertical facies variations and stacking patterns comparable to Khuff Formation carbonates of the subsurface of the Middle East. Thicker-bedded, shallow subtidal, high-energy grain-dominated carbonates developing around high-frequency maximum flooding surfaces and thinner-bedded peritidal, low-energy mud-dominated and often microbial-laminated carbonates underlying parasequence boundaries and high-frequency sequence boundaries are features that can be well observed in this dataset. Structural features such as fracture networks, collapse features, vertical low-offset faults and mechanical stratigraphy observed at the outcrops are also captured and documented to help understand fluid flow behavior.

All supporting geological interpretation and information are linked interactively to the LiDAR dataset using point-and-click menus to enhance its effectiveness. The 3-D virtual product captures the valuable knowledge of LiDAR scanned outcrops in a fashion that can be used for self-study, training, and pre-field trip and workshop discussions.

Introduction

Knowledge and technology are key resources and long recognised as being of central importance to any organization and contributing to business success. In oil and gas sectors, knowledge and technology have helped companies to sustain their positions and adapt themselves to the challenging operating environments and declining resources. Ability of these companies to reduce operating costs and maximizing recovery is significantly impacted by the quality of knowledge and technology employed into the development plan, especially in the assessment of subsurface environments.
An Assessment of the Influence of Micro-porosity for Effective Permeability Using Local Flux Analysis on Tomographic Images
Authors: Apourvari Saeid Norouzi , Arns Christoph H.
Published: March 2015

Carbonates are typically heterogeneous over multiple length scales. Due to varying connectivity of pore space features at different scales for carbonates, exhibiting bi-modal or multi-modal pore size distributions, the reliability of petrophysical cross-correlations for predicting the transport properties is reduced. The recent emergence of high resolution micro-CT technology in conjunction with robust numerical methods helps to address this problem.

Due to the finite resolution of X-ray images current pore scale flow models only consider macro-pores; the pores which are resolved at the image resolution. The importance of micro-pores in fluid flow and solute transport has been proved, although qualitatively, in many applications including hydrocarbon production from carbonate rocks, CO2 storage and subsurface groundwater remediation. In this study we quantify the effect of microporosity on effective permeability for different porous media with exhibiting a varying amount of micro- and macro-porosity. We combine Gaussian random fields (GRF) and particle based models to construct model structures with dual-scale pore types. The Brinkman equation is solved directly on the images to calculate the effective permeability via the lattice Boltzmann method while quantifying the flux through the micro-porous regions.

Connectivity analysis conducted on the samples revealed the connectedness of macro-pores through micro-pores. Micro-porosity incorporation increased the connectivity of the macro-pores and consequently the effective permeability of the whole system. This paper introduces a methodology to quantify the effect of microporosity on the fluid flow and incorporate it into the macropores. The approach was first tested on three homogeneous model structures and images of two sandstone rocks, before being implemented on more heterogeneous model structures with bi-modal pore size distribution. The work presented here enables us to couple the effect of sub-resolution pores and macropores in a physically meaningful way. This approach might have important applications to the calculation of permeability for unconventional reservoir rocks.
A New Treatment Technique of Produced Water from Polymer Flooding
Authors: Wang X. , Liu R. , shao Z. , Miller J. H. , Wakasiki S. , Lisana R.
Published: March 2015

After the water flooding process or secondary oil extraction, the tertiary oil extraction has been widely used in Chinese oilfield in recent years. Although this technology can enhance the oil recovery by up to 12%, it also produces more and more polymer-flooding wastewater as byproduct per year. Without proper treatment, the oil pollutant pollutes and poisons the water and atmospheric environment. Removing polymer and oil from the oilfield produced water is an important aspect of pollution control in oil and gas industry of China.

One of the major technical requirements of the crude oil exploitation industry is to minimize the concentration of hydrolyzed polyacrylamide (HPAM), crude oil and suspended solid (SS) in the oilfield polymer-flooding wastewater and realize the reuse of this wastewater. In this study, the membrane technology was used to achieve this goal in laboratory-scale dead-end test unit with flat polyvinylidene fluoride (PVDF) membrane (MW 100 kDa). We systematically inspected the membrane fouling mechanism, the variety of total membrane resistance, total fouling resistance, the dominant resistance, membrane fouling driving force and the filtration proceeds in the filtration process.

The orthogonal method and multivariate linear regression method were applied to analyze the influencing degree of the main pollutant concentration on the critical flux. According to comparison of the average rates of change of the critical flux for the HPAM concentration, oil concentration and SS concentration in single solute solution, double solute solution and oilfield polymer-flooding wastewater, HPAM can decrease the average rate of change of the critical flux for other two solutes and has the crucial effect on the critical flux.

According to this research, the ultrafiltration membrane technique can be efficiently used to treat synthetic oilfield polymer-flooding wastewater. A standard procedure is developed to be a methodology reference for the wastewater treatment.
From feasibility to seismic operations: a time-lapse seismic pilot project on Al Khalij field - Offshore Qatar
Authors: Pagliccia Bruno , Cantin Fabrice , Brechet Emmanuelle , Brosille Eddy , Blanco Benoit , Charron Patrick , Emang Michael , Radigon Michel
Published: March 2015

Time lapse seismic survey (aka 4D seismic) is a geophysical tool used by the industry to guide and maximize field development. It has been proven successful mainly in clastic deposits environment (Gulf of Mexico, Gulf of Guinea, North sea,…) but sparsely tested on carbonate fields because of seismic quality concerns.

Total E&P Qatar engaged in 2012 a "proof of concept" 4D pilot study on its operated Al Kahlij field - offshore Qatar- to demonstrate the value of information provided by a 4D seismic in a middle-east carbonate field under development. This study is made of:

A feasibility study which aims to quantify the expected 4D effect by using a petro-elastic model and several chosen depletion scenarii. These input data are used to compute a synthetic time-lapse seismic dataset through a massive seismic modeling.

A 4D pilot seismic survey shot in summer 2012 (monitor) which was designed to repeat the first seismic survey shot in 1998 (base).

A dedicated seismic processing of both base and monitor in Total's 4D processing dedicated center followed by a specific inversion process (time warping) to extract the awaited 4D signal.

The main objective on Al Khalij field is to validate that 4D seismic is able to calibrate the reservoir model and make it more predictive.

If successful, the time-lapse seismic survey concept can be envisaged for other carbonates field in Qatar and in the Arabic Gulf area for field development optimization.

Introduction

The Al Khalij field is an oil producing field located in Block6, offshore Qatar (Figure 1). Total E&P Qatar has been developing the field with Qatar Petroleum since 1996. A 3D seismic survey was shot in 1998 and has been processed several times until 2009 to build the reservoir model used to monitor and further develop the field.

The Al Khalij field is situated in transition zone, its water production rapidly increased to reach around 90% water-cut. Water arrival on the field is complex and implies several kinds of phenomena: short and long range injections, bottom and edge aquifer, large scale conductive events bringing water influx, etc. The field yields however large remaining reserves and it is planned to redevelop it. A better understanding of the water behavior is needed at a larger than well scale. Time-lapse seismic is a proven technique in clastic environments to assess fluid saturation changes both in time and space. Its efficiency in carbonate environments is still to be demonstrated in the Arabian gulf area.
Nitrified Water as UBD Medium - Perfect Recipe for a Corrosion Nightmare:: Issues and a Solution
Authors: Hussain Iqbal , Al-Enezi Dakhil , Al-Khaldy Ali , Sulaiman Sulaiman , Hayat Sara
Published: March 2015

Kuwait Oil Company embarked on an ambitious project to look for gaseous Hydrocarbons in a hitherto un-proven formation in the North Kuwait Field. As the target formation was extremely depleted and usually was drilled through under-total-loss conditions, these wells were designed to be Under-Balanced-Drilling (UBD) wells.

The design conditions for an Under-balance or drawdown of 10% below formation pressure of the target zone called for Nitrified water as the fluid medium. Design simulations showed a normal Nitrogen pumping rate of around 1100 scfm for maintaining the UB conditions. Further testing of the target formation called for a huge drawdown of a maximum of 30%. This led to extreme conditions of pumping Nitrogen at the rate of 2000 scfm. The normal operating conditions with membrane NPU resulted in 5% Oxygen being pumped in with Nitrogen. This resulted in a highly corrosive environment under Bottom-hole conditions, especially when we started producing highly saline formation water. The above conditions led to very severe corrosion of our Drill string and UBD Coring equipment, creating a potential hazard of losing our whole string.

Conventional corrosion inhibition completely failed to arrest the corrosion of the string. This led to intensive study and debates within the team to find a solution to the problem and quickly too. A multi-pronged solution comprising of controlling pH, usage of Phospate Ester Inhibitor formulation, filming amine and monitoring through usage of Corrosion coupon rings in the drill string led to a dramatic improvement of the corrosion damage.

Corrosion hazards in UBD wells are a reality and a heady-mix of ideal conditions for corrosions could mean disaster. Conventional Corrosion programs usually fall short of dealing with the severe corrosion existing down-hole. Special operations such as Underbalanced Coring could fail dramatically before achieving objectives. A multi-pronged approach needs to be designed and the severity of the problem understood before embarking on such ambitious projects. The authors are going to present a strategy for putting the best foot forward when dealing with such issues. Being forewarned will always mean being forearmed.

Introduction

Residual oxygen in membrane generated Nitrogen, when commingled with Potassium or Sodium Chloride drilling brines or filtered brackish water as drilling fluid creates a very corrosive environment downhole. This leads to severe corrosion of all tubulars such as drill pipe, casing and tubing. Corrosion has been the culprit of many doomed projects in the early days of UBD.
An Accurate Volumetric Calculation Method for Estimating Original Hydrocarbons in Place for Oil and Gas Shales including adsorbed Gas using High-Resolution Geological Model
Authors: Bruyelle Jeremie , Guerillot Dominique
Published: March 2015

The emergence of liquid-rich and gas shale reservoirs presents major strategic opportunities and challenges for the oil and gas industry. Accurate estimation of Stock Tank Oil and Gas Initially In Place (STOIIP & GIIP) is one of the priority tasks before defining the reserves. An accurate method is proposed to calculate hydrocarbon volumes using high-resolution geological models taking advantage of huge improvements made during last decade in the field of characterization and geological modeling of unconventional reservoirs. This exact method provides fluids in place in reservoir and surface conditions with an extended black-oil formulation including condensates. The physic including the equilibrium between gravity and eventually capillary forces and adsorbed gas is fully respected using, for each lithofacies, the most accurate available geological description with 3D porosity distributions, Langmuir isotherms (Langmuir, 1918), capillary pressure curves, and thermodynamic data. Adsorbed and liquid-rich gases are considered.

This method calculating hydrocarbons in place is the natural endpoint of any workflow devoted to the geological modeling of newly discovered reservoirs, particularly suited to heterogeneous reservoirs.

The knowledge generated by this calculation has significant impact on fracturation programs to increase the recovery rate and field development planning.

Introduction

The characterization of volume of fluids in place in shale reservoir is a challenging task for many reasons, in particular because of the adsorbed gas which is a way of trapping gases in geological formations. The adsorption capacity of a gas on a rock depends on many parameters such as temperature, pressure, gas type and rock type. Shale gas is generated in source rocks, which are usually made of clay with high organic matter content. However, the organic content depends on the maturity of the organic matter from which they come from. Also, the maturity of the organic matter itself depends on the temperature history during the reservoir formation. Thus, in the same sedimentary basin, conventional reservoir can be formed from hydrocarbon expelled of unconventional reservoir. This is the case in the United States, where sedimentary basins that produce large quantities of unconventional hydrocarbons were already conventional oil and gas basins exploited for their conventional hydrocarbons. As for conventional reservoirs, there are large uncertainties on many parameters of the geological model. For shale reservoirs, another source of uncertainty is being added due to specific parameters related to them. Shale makes a wide variety of highly differing formations. All these formations differ from conventional reservoirs, and shale rock characteristics can differ from shale to shale, and even within the same shale.
3D Imaging of Porosity Modifying Phases in Shuaiba Reservoir, Al Shaheen Field
Authors: Marquez Ceballos X. , Solling T. , Finlay S. , Bounoua N. , Gagigi T.
Published: March 2015

Existing porosity and permeability predictions in the Shuaiba reservoir of the Al Shaheen Field are largely based on detailed core observations and measurements that have been integrated with geochemical data and linked to robust conceptual models. This approach has been successful at predicting general porosity and permeability trends mainly related to deposition on the platform, barrier and basinal environments and the processes of dissolution and cementation; however, there is a lot of uncertainty in correlating and predicting the spatial variation of dissolution and cementation styles within each depositional environment. This uncertainty becomes larger when trying to identify rock types for petrophysical prediction and also to correlate the diagenetic patterns at field scale.

The work summarized in this contribution demonstrates how we have gone beyond the classic characterization of diagenesis and have moved toward the quantification and 3D visualization of diagenetic products that modify the pores and pore throats. Present day porosity and permeability of the Shuaiba limestones in the platform area has been significantly modified by calcite and minor pyrite cementation, hence in this study detailed and calibrated paragenetic data have been integrated with 2D quantitative mineral and elemental maps obtained with the use of QEMSCAN and coupled with 3D images using an in-house micro-CT scanner. Meticulous segmentation of grey levels in the 3D micro-CT images allowed the recognition and quantification of the cement phases and corresponding porosity before cementation, which could then be reconstructed and used to assess the porosity at any given diagenetic stage. This integrated, object-based, approach has the potential to significantly improve our ability to identify rock types, to help predict the spatial distribution of porosity and permeability in the Shuaiba reservoir and to ultimately improve realizations of reservoir connectivity for flow simulation.
Quantifying the Impact of Natural Fractures and Pore Structure on NMR Measurements in Multiple-Porosity Systems
Authors: Chi Lu , Heidari Zoya
Published: March 2015

This paper quantitatively evaluates the hierarchical structure of multiple-porosity systems, including natural micro-fractures, inter-granular, and intra-granular pores, using nuclear magnetic resonance (NMR) measurements. Conventional well logs cannot distinguish between different pore structures. NMR measurements, although counted among the most reliable methods to measure formation porosity, has been conventionally considered as insensitive to the existence of natural fractures. Thus, the impact of natural micro-fractures on NMR measurement has rarely been investigated.

We simulated NMR response in porous media using a random-walk algorithm. We randomly distributed and oriented natural micro-fractures in various porous rock matrices. We then quantified the sensitivity of NMR T2 (spin-spin relaxation time) distribution to the presence of natural fractures within three-dimensional (3D) Micro-Computed Tomography (micro-CT) images of carbonate and sandstone rock samples andsynthetic organic shale matrices.

Results from synthetic rock samples showed that NMR T2 distribution can be significantly affected by aperture, concentration, and shape (e.g., needle-like or planar shape) of natural fractures, as well as size and connectivity of inter-granular pores. We also quantified the impact of diffusional coupling effect between the micro-fractures and inter-granular pores on NMR T2 distribution. Applications of this research include reliable reservoir characterization in challenging multiple-porosity systems such as naturally fractured carbonates and organic-rich source rocks, whereconventional well logs cannot reliably characterize the complex pore structure andinterpretation techniques for unconventional logs such as NMR are not fully developed.
The effect of alkaloids present in blue lupine (Lupinus angustifolius) seeds on the growth rate, selected biochemical blood indicators and histopathological changes in the liver of rats
Authors: Stanek Maria , Rotkiewicz Tadeusz , Sobotka Wiesław , Bogusz Jacek , Otrocka-Domagała Iwona , Rotkiewicz Agnieszka
Published: March 2015

The objective of this study was to determine the effect of alkaloids present in blue lupine (Lupinus angustifolius) seeds on the growth rate, selected indicators of carbohydrate and lipid metabolism, and liver morphology in rats. The experimental material comprised 32 Wistar rats at around 3 weeks of age, with an initial body weight of 81 g. During a 28-day feeding trial, the rats were fed diets containing the seeds of three blue lupine cultivars, Baron, Zeus and Wersal, with different alkaloid concentrations (0.36, 0.41, 0.56 mg/kg, respectively). Diets containing the seeds of three blue lupine cultivars reduced the feed intake and significantly limited the growth rate of experimental rats, compared to the control group. Lupine alkaloids had no effect on the serum concentrations of glucose and total cholesterol in rats, whereas elevated triglyceride concentrations were noted in experimental groups, relative to the control group. Diets containing the seeds of blue lupine cultivars Zeus and Wersal induced changes in alanine transaminase activity. A histopathological analysis of the liver revealed parenchymatous degeneration, which was more advanced in rats fed diets with the seeds of blue lupine cultivars Zeus and Wersal than in the control group, and congestion of portal vessels, which was more severe in rats fed the seeds of blue lupine cultivars Baron and Zeus.
Intensive training technique utilizing the dog’s olfactory abilities to diagnose prostate cancer in men
Authors: Urbanová Lucie , Vyhnánková Vlasta , Krisová Šárka , Pacík Dalibor , Nečas Alois
Published: March 2015

Carcinoma of the prostate is a commonly occurring malignant tumour in men and is a common cause of death. Early diagnosis and therapy is crucial for the successful treatment of this serious disease. It is therefore desirable to develop a sufficiently reliable, minimally invasive, and inexpensive method of diagnosing prostate cancer, which would usefully supplement the diagnostic techniques currently in common use (digital rectal examination, measuring the prostate-specific antigen level in serum, transrectal ultrasonography). This article describes in detail the methodology of a new technique for intensive training aimed at developing the dog’s olfactory abilities to diagnose carcinoma of the prostate in men while the animal is still young. At the same time, the rate of success in establishing the diagnosis of prostate cancer in men using this method was evaluated based on the identification of urine samples from patients in whom the disease was histologically confirmed. The results of our study demonstrate that the diagnosis of prostate cancer in men using the olfactory abilities of a specially trained dog can be considered a reliable, non-invasive, and relatively inexpensive method of diagnosing carcinoma of the prostate.
Observations of supercooled water and frazil ice formation in an Arctic coastal polynya from moorings and satellite imagery
Authors: Ito Masato , Ohshima Kay I. , Fukamachi Yasushi , Simizu Daisuke , Iwamoto Katsushi , Matsumura Yoshimasa , Mahoney Andrew R. , Eicken Hajo
Published: March 2015

Formation of supercooled water and frazil ice was studied in the Chukchi Sea coastal polynya off Barrow, Alaska, USA, in winter 2009/10, using moored salinity/temperature sensors and Ice Profiling Sonar (IPS) data along with satellite data. Oceanographic data from two moorings revealed episodic events of potential supercooling at 30–40m depth, including the possibility of in situ supercooling, while the polynya was open. We identified frazil ice-like signals in the IPS data down to 5–15 m depth, associated with large heat loss and windy, turbulent conditions in an active polynya. This likely represents the first IPS observation of frazil ice in the marine environment. On the day of the maximum signal of frazil ice, spaceborne synthetic aperture radar shows streaks of high backscatter within the polynya, indicating active frazil ice formation just downwind of the mooring sites. In addition, the longer-term potential supercooling that persisted for 1–3 weeks occurred twice despite the absence of polynya activity at the mooring sites. These events occurred during periods dominated by the northeastward current. A series of coastal polynyas had formed southwest of the mooring sites prior to these events. Thus, the water masses with potential supercooling were likely advected from these polynyas.
Study of Umbilical Cord in Pregnancy Induced Hypertension with and without Diabetes Mellitus
Authors: Saha Rita Rani , Farhat Nazma , Karmaker Mallika
Published: March 2015

Context : Two organs that can provide a good insight into pregnancy induced hypertension with and without diabetes mellitus are the placenta and the umbilical cord along with their vessels. In the present study the umbilical cord is taken from the placenta of hypertensive and diabetic mothers to measure its diameter, to observe contained vessels and its mode of attachment to the placenta. Materials and Methods: An observational and analytical type of study was conducted in the department of Anatomy, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka between November 2003 to May 2004 on umbilical cords. To study the umbilical cord, placentas were collected from fifty eight Bangladeshi women who gave birth to a single live baby through Caesarian section after 35 to 40 weeks of gestasion. Twenty of the mothers were non hypertensive, non diabetic control, twenty had pregnancy induced hypertension(PIH) and eighteen had pregnancy induced hypertension and gestesional diabetes mellitus(PIH+GDM). Results: No significant difference was found between any groups for diameter of the umbilical cord. All the umbilical cords had same number of vessels. There was variation among the mode of insertion of umbilical cord. Conclusion: Diameter of umbilical cords did not show significant difference in either of the two diseased groups with the control group in the Post Hoc option of analysis of variance (ANOVA) at 5% level. DOI: http://dx.doi.org/10.3329/bja.v12i1.22609 Bangladesh Journal of Anatomy, January 2014, Vol. 12 No. 1 pp 03-06
Sexual Dimorphism in Alar Length and Auricular Index of Sacrum
Authors: Kamal AHM Mostafa , Ara Shamim , Begum Shahanaz , Hoque Md Mesbahul , Khatun Khadeza
Published: March 2015

Context : It has long been customary among anatomists, anthropologists and forensic experts to judge the sex of the skeletal material by non-metric observations. Afterward the study of sexual divergence has been based upon actual measurements in different bones. The study in relation to metrical data on bone is very few in our country. The study was planned to observe the differences of sacra between male and female in respect to measurement of alar length and auricular index of sacrum. The findings of this study might be useful in providing morphometrical data that can be used by anatomists, forensic experts, anthropologists, orthopedic surgeons and neurologists for proper initiative in their respective fields. Materials and Methods: A cross-sectional, analytical type of study was performed in the department of Anatomy, Dhaka Medical College, Dhaka from January 2011 to December 2011. A total of 172 (one hundred seventy two) adult human dry sacra of unknown sex was assessed. The study samples were distributed in male and female sex groups by discriminant function analysis. All the samples were studied morphologically. Length of ala and auricular surface were measured with the help of digital slide calipers. Results: The mean length value of ala was greater in female than male (P<0.001). The difference between the mean value of alar index in male and female was significant (P >0.05). The mean value of auricular index was higher in male than female and the difference was statically significant (P<0.001). Conclusion: The sacrum can be used for sexual dimorphism as is usual in anthropological work. The knowledge of alar length and auricular index of sacrum is essential in medico-legal practice for sex determination of an individual. DOI: http://dx.doi.org/10.3329/bja.v12i1.22613 Bangladesh Journal of Anatomy, January 2014, Vol. 12 No. 1 pp 17-21
Gross and Histomorphologic Study of the Umbilical Cord in Pre-gestational Diabetes Mellitus and Gestational Diabetes Mellitus
Authors: Alam Md Rafiqul , Momen Md Abdul , Sultana Anjuman Ara , Hassan SM Nurul
Published: March 2015

Objective: The umbilical cord is fetal organ and contains two arteries and one vein covered by connective tissue called Whartons jelly. Gestational diabetes mellitus (GDM) is a common metabolic disorder, the importance of which includes possible fetal and maternal complications. As the umbilical cord is the communicating channel between the fetus and the placenta, any pathological change in the umbilical cord may cause harm to the fetus. For this reason, some gross morphological and microscopic features of umbilical cord were analyzed in case of pre-gestational and gestational diabetes mellitus. Materials and Methods: A cross-sectional, analytical and observational type of study was carried out in the Department of Anatomy, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka between July 2004 and December 2005. Total 60 umbilical cords with placentae were collected within 34 to 40 weeks of gestation from BSMMU and BIRDEM. Among these, twenty were from mothers not suffering from diabetes (Control group), twenty had pre-gestational diabetes mellitus (PDM group) and twenty were suffering from gestational diabetes mellitus (GDM group). Number of umbilical vessels were observed on the cut surface of umbilical cord later confirmed by histological examination. Presence or absence of true or false knots were noted. The umbilical cord cross sectional area, vessel areas and their luminal area were estimated. The ANOVA post-hoc option was used for statistical analyses of results. Results: Among the gross and histomorphological variables of the umbilical cord, there was no significant difference between the three groups. DOI: http://dx.doi.org/10.3329/bja.v12i1.22615 Bangladesh Journal of Anatomy, January 2014, Vol. 12 No. 1 pp 25-29
Psychiatric Morbidity among Caregivers of Schizophrenia Patients  A Study in Tertiary Care Psychiatric Hospital in Dhaka
Authors: Uddin MM Jalal , Alam Md. Tariqul , Ahmed Helal Uddin , Khan Niaz Mohammad , Hamid MA , Chowdhury Waziul Alam , Rabbani Md. Golam
Published: March 2015

Background: Severe mental illness like schizophrenia has far-reaching consequence for both patients and caregivers and their relatives and they also experience feeling of loss and grief. They are confronted with uncertainty and emotion of shame, guilt and anger like the patients they feel stigmatized and socially isolated. Caring for a family member with schizophrenia is an enduring stressor and causes considerable amount of burden. Objective: To assess mental health status of the caregivers of schizophrenia patients. Methodology: This descriptive cross sectional study was done among the caregivers of schizophrenia patients in outpatient and inpatient department of National Institute of Mental Health (NIMH), Dhaka, Bangladesh from September 2010 to February 2011. A semi-structured Questionnaire and General Health Questionnaire-28 (GHQ-28) were applied to the caregivers of schizophrenia patients who fulfilled the inclusion criteria. Among the respondents whose GHO-28 score were 4 or above Structured Clinical Interview for DSM-IV Axis I Non Patient (SCID-I/NP) version was applied to identify psychiatric disorders among the caregivers of schizophrenia.Results: Out of 272 respondents most of them were female (88.97%), housewife (72.42%) of 21 to 50 yrs age (80.51%). In this study 22.43% of respondents were suffering from different types of mental disorders. Among them major depressive disorder were most prevalent (11.8%). Other psychiatric disorders were found generalized anxiety disorder (4.8%), pain disorder (2.9%). Less common were panic disorder, social phobia, adjustment disorder and undifferentiated somatoform disorder (0.7% in each type).Conclusions: Significant proportions of the caregiver of schizophrenic patients were suffering from psychiatric disorders that did not get any psychiatric treatment.Journal of Current and Advance Medical Research 2015;2(1):12-17DOI:  http://dx.doi.org/10.3329/jcamr.v2i1.22581