bluuebunny/crossref_metadata_2025 huggingface dataset:
Is Your Trap Filled to Spill?
Authors: Peacock Douglas
Published: May 2016

Gross rock volume is typically the biggest uncertainty in volumetric estimation, especially early in field life. Assumptions about fluid contacts are often the biggest component of volumetric uncertainty. This paper will examine how a better understanding of hydrocarbon trap and seal capacity allows more accurate volumetric estimates and improved risk assessment.

Recent advances in several areas such as basin modelling, hydrocarbon charge, seal capacity and fault seal analysis have allowed a more comprehensive understanding of hydrocarbon traps. Hydrocarbon charge studies indicate that the proportions of generated hydrocarbons that are trapped in conventional reservoirs, the trapping efficiency, are very low, in the order of a few percent. Many times more hydrocarbons are generated than traps have the capacity to store.

Analysis of individual fields suggests that many traps are filled to capacity rather than to structural spill points. Fill capacity may be limited due to lack of top seal or fault seal. Fields that are not filled to structural spill are often limited by trap capacity rather than by insufficient charge. Hydrocarbon phase in a trap is affected not only by source rock type and maturity, but also by seal capacity.

With exploration wells often targeted at or near the crest of structural highs, over-optimistic assumptions about fluid contacts, in particular an assumption of fill-to-spill is a major cause of misunderstanding volumetric uncertainty.

These observations and results have implications throughout the life cycle of a field, from risk assessment of prospects to estimation of volume ranges during exploration, appraisal and development.

Look-backs and post-mortems are also useful to assess whether previous assumptions about hydrocarbon charge, seal capacity and fill mechanisms have been accurate or if they need revision. Analogues and lessons learned from existing fields and discoveries can also provide valuable insight into future predictions. Assessing volumetric uncertainty in terms of trap and seal capacity rather than relative to structural spill points allows better quantification of volumetric uncertainty.

Hydrocarbon Generation and Trapping Efficiency

Previous studies of hydrocarbon trapping efficiency have suggested that a relatively small proportion of generated hydrocarbons are conventionally trapped. Large proportions of the hydrocarbons generated are retained in the source rock without migrating, and remain as targets for unconventional reservoir development. Of the hydrocarbons that are expelled from source rocks, most are lost to the surface or are retained in carrier beds. The proportion of hydrocarbons captured in conventional traps is estimated to range from a few percent to around ten percent. Figure 1 highlights the large proportion of hydrocarbons retained in the source rock, but also shows the relatively small amount of conventionally trapped hydrocarbons. Expelled hydrocarbon volumes are typically many times greater than trapped hydrocarbon volumes.
A Broadband Seismic Acquisition and Processing Solution to Improve Imaging in a Complex Shallow Water Environment, Malaysia
Authors: Spedding Andrew , Gehman Carter , Nyein Glenn , Sazykin Artem , Vasilyev Pavel , Wurfel Monica
Published: May 2016

There have been several recent advances in the last few years in marine broadband acquisition and processing technologies and shallow gas imaging. They have enabled new life to be breathed into old datasets through reprocessing and from completely new seismic surveys to be acquired in place of legacy conventional datasets that can lead to a step change in data quality and subsequently reservoir understanding. This paper will look at these new technologies and give an example of a shallow water dataset with complex near surface shallow gas bodies where a combination of new acquisition, processing and reprocessing techniques have been able to provide significant uplift over pre-existing legacy conventional datasets targeting thin bed pay zones. Careful consideration of the geophysical challenges and implementing targeted solutions has been a key to producing a successful output. A complimentary paper discusses in more detail the interpretational benefits of the new acquired broadband data versus the legacy conventional data.

Introduction

Until recent years marine seismic datasets have had to contend with the source and receiver ghost notch effect in the output frequency spectrum whereby the outgoing upward travelling source side sea-surface reflection and the returning receiver side sea-surface reflection constructively and destructively interfere with the directly down going source reflections and up going receiver side reflections to give band limited datasets. Geophysicists have had to design their surveys to enhance a given part of the bandwidth at the detriment to another part e.g. tow shallow to enhance higher frequencies or tow deep to enhance low frequencies. With the advent of broadband acquisition techniques (Hill et al., 2006; Carlson et al., 2007; Soubaras and Dowle, 2010) this no longer has to be the case and the recorded ghosts can be addressed in acqusition based solutions to give frequency rich broadband datasets that can almost reduce the wavelet to a near spike. As a by-product streamers can be towed deeper to reduce the effects of noise from sea state generated noise to provide datasets with higher signal to noise and aiding better lower frequency penetration deeper into the section. The result is rich bandwidth shallow data and better imaged deeper sections.
Asia-Pacific’s First Isometrically Sampled Subsurface Image: Innovative Technology to Deliver on Complex Field Development
Authors: Fitzpatrick Jeremy , Iwachow Dana , Bayly Martin Paul , Roth Jurgen
Published: May 2016

Introduction

This case study describes the motivation and execution of a large 3D surface seismic survey recently conducted over 4,000km2 in the Carnarvon Basin offshore Australia. This survey was the first use of an innovative towed streamer technology in Australasia that enables the collection of broadband, un-aliased isometrically sampled wavefields.

Woodside Energy Ltd (Woodside) operates the North West Shelf gas producing assets that are located on the Rankin Platform, Parker Terrace, Kendrew Trough and also oil fields of the Madeline Trend. Certain areas in the vintage 3D surveys are characterized by poor seismic data quality producing uncertainty in reservoir management and potential prospectivity. In 2012 the North West Shelf (NWS) Project participants held a technical workshop to determine a strategy to maximize the productive life of this acreage and to extend the production from the Karratha gas plant. A key outcome of the workshop was the need for new 3D seismic data of a quality suitable for appraisal, development and exploration activities over the next decade. This resulted in the decision in late 2013 to acquire the "Fortuna 3D" (Fortuna) seismic survey, covering over 4,000km2 (Figure 1). The resulting seismic image is intended to enable the NWS joint venture to explore and develop this core asset with greater confidence.

Fortuna is the first survey in Australia to use a new multi-sensor towed streamer technology. This streamer includes both finely spaced hydrophones and accelerometers embedded in the cable. These streamers digitally measure not only the scalar pressure wave with finely spaced hydrophones as in conventional systems, but also use accelerometers to measure the directional particle acceleration of the seismic wave in both the vertical (Az) and cross-cable (Ay) directions. These additional measurements when carefully combined provide a broadband frequency signal that allows the reconstruction of the seismic wavefield with fine spatial sampling to improve both noise attenuation and subsequently the subsurface image. This "three component" streamer technology was augmented with other innovations including multilevel seismic sources, integrated real time navigation and streamer steering along with massive computing resources to facilitate data conditioning and initial signal processing on the vessel.

As shown in the map in Figure 1, the Fortuna survey presented several operational challenges including concurrent oilfield operations, working around infrastructure and other vessels, plus environmental challenges associated with strong tides and unpredictable currents. These issues required careful forecasting and planning due to the dynamic nature of this operational environment.
Reservoir Characterization through Bayesian Joint Inversion of Seismic and EM Attributes
Authors: Miotti Fabio Marco , Ceci Federico , Guerra Ivan , Lovatini Andrea
Published: May 2016

The main objective of the reservoir characterization is to provide reservoir property maps to reservoir engineers for the field appraisal. Since that porosity and water saturation affect both seismic and EM attributes, their estimation can reduce the uncertainty of the interpretation and consequently the costly drilling of un-productive reservoirs. This study explains the petrophysical joint inversion (PJI) of seismic and EM attributes to estimate the petrophysical model in terms of porosity and water saturation. Rock physics models are involved as forward models to form a proper link between data input (seismic and EM attributes) and the petrophysical parameters, (porosity and water saturation). According to the formal Bayesian theory, the uncertainty affecting the input data (AI and resistivity models) and the model parameters (porosity and water saturation) is captured by, respectively, data and model covariance matrix. It is assumed Gaussian probability density functions for model parameters and input data. PJI is applied where both seismic attributes and resistivity models show consistent anomalies as evidence of a potential reservoir. PJI objective is to jointly estimate porosity and water saturation from AI (seismic inversion derived), and resistivity (CSEM inversion derived), by using rock physics modeling within Bayesian framework. The result is represented by the porosity and water saturation distribution within the potential reservoir. PJI realizes a multi-physic inversion able to exploit the complimentary information available in the single physic domains, which are seismic and EM. The methodology is applied to a real hydrocarbon exploration scenario to evaluate its contribution to the interpretation phase. 3D volumes of estimated porosity and saturation show how the joint inversion of acoustic impedance and electrical resistivity provide a quantitative description of the reservoir properties and with it a measure of uncertainty, which is consistent with the petrophysical model and observations.

Introduction

Reservoir characterization objectives are to estimate the petrophysical properties of the prospective hydrocarbon traps and to reduce the uncertainty of the interpretation. In this framework, we present a workflow for petrophysical joint inversion of seismic and EM attributes to estimate the petrophysical model in terms of porosity and water saturation. This study realizes the joint inversion within the probabilistic structure provided by the Bayesian theory. 3D volumes of estimated porosity and saturation, show how the joint inversion of acoustic impedance and electrical resistivity can provide a quantitative description of the reservoir properties and with it a measure of uncertainty, which is consistent with the petrophysical model and observations.
New Thermal Data and Challenges of Heat Flow Variations Evaluation for Basin Petroleum Exploration
Authors: Popov Yury Anatolievich , Popov Evgeny , Miklashevskiy Dmitriy , Korobkov Dmitriy Aleksandrovich
Published: May 2016

The present work summarizes the results of analysis of unique experimental data on vertical heat flow variations in different geological structures obtained from 15 scientific supper-deep and deep boreholes drilled to the depths of 1600–12262 m within Russian and ICDP programs. The new workflow was applied for the heat flow estimation which is based on (1) precise and detailed thermal conductivity measurements on more than 30000 cores with the new emerging technologies, (2) usage of more than 100 equilibrium and non-equilibrium temperature logs, and (3) determination of conductive heat flow component within 20–100 m intervals along every borehole studied.

The data on conductive heat flow variations provides an estimate of vertical variations in the convective heat flow component. The latter reflects the information on variations in reservoir and formation properties and heat- and mass transfer processes in reservoirs and formations.

It was established that a conductive component of the heat flow varies between 70 and 100% for the boreholes studied with essential (up to 100%) increase in heat flow within upper depth intervals of 2–4 km in some cases. Terrestrial heat flow values established from the measurements in deep and super-deep boreholes exceed the previous experimental heat flow estimates by 30…130% depending on a region of drilling. During the previous estimates the heat flow values were obtained from the measurements in shallow boreholes and heat flow was determined from averaging temperature gradient and thermal conductivity along boreholes.

The established heat flow variations play an important role in the improvement of reliability of basin and petroleum system modeling and prediction of temperatures below the borehole depths. The use of calibrated heat flow distributions is shown to increase the confidence of such studies.

Introduction

Experimental data on heat flow density and rock thermal properties (thermal conductivity and volumetric heat capacity) are critically important for basin and petroleum system modeling. The results of the modeling depend essentially on heat flow density values and thermal property values for the sedimentary basin under studying integrated in the model. The rock thermal properties determine formation thermal regime in its natural state as borehole as at thermal methods of EOR.

It is considered normally that satisfactory data on heat flow and thermal properties could be found in publications and it is a usual practice in oil/gas science and industry at basin and petroleum modeling at present.
Influence of Small-Scale Lateral Heterogeneity on Seismic Velocity Analysis and Time-to-Depth Conversion
Authors: Takanashi Mamoru
Published: May 2016

Reservoir depth map is often produced by the time structure map and vertical velocity estimated based on seismic (stacking) velocity analysis. Although seismic velocity is generally the only available velocity information away from well locations, it may not match with the velocity estimated at well locations. VTI (transverse isotropy with vertical symmetry axis) is widely recognized as a typical source of difference between the seismic and vertical velocities and hence the misties in time-to-depth conversion. However, small-scale lateral heterogeneity (LH), often associated with velocity lenses such as channels in the overburden, can cause more significant errors in both time- and depth-domain velocity analyses. I discuss the influence of a thin laterally heterogeneous layer on the normal moveout (NMO) velocity for stratified media using an analytic description. The analytic result shows that distortion of the seiemic velocity is caused primarily by lateral velocity curvature (i.e., by lateral velocity variation with the scale smaller than the maximum offset). The heterogeneity-related distortion increases with the maginitude of velocity contrast and with the target depth. Furthermore, application of the Dix differentiation (used for conversion from NMO velocity to interval velocity) can significantly amplify the lens-induced distortion. The analytic results also indicate that small velocity errors can increase with depth in migration velocity analysis as well. A field example shows that lens-induced 20–30 ms time distortion (pull-up or push-down anomalies) leads to a few hundred m/s errors in the seismic velocity, which are close to the results estimated by the analytic method. The presented analytic approach should help quick evaluation of the seismic velocity analysis and prevent from significant errors in reservoir depth estimation.
Efficient Reservoir Modeling-Statistical Approach for Evaluation and Development of Future Waterdrive Undersaturated Oil Reservoir Performance
Authors: Al-Mudhafer Wathiq Jassim Mohammed , Al-Khazraji Ahmed Jaber
Published: May 2016

For achieving optimal reservoir management, an insight view towards good understanding of the reservoir behavior should be attained. Then, an efficient design of integrated reservoir modeling is a crucial requirement for planning of an optimal future development especially in mature oil fields. The field under study is South Rumaila oil field/ main pay. It is a mature oil field located in South of Iraq with around 59 years of production history. It has 40 producing wells and 20 injection wells located only at the east flank to maintain the reservoir pressure since there is an infinite acting edge water aquifer and its strength from the west flank is much effective more than the east flank. A reservoir simulation study has been done to determine the optimal future reservoir performance in regards to the effectiveness of water injection to improve oil recovery.

In this paper, multiplicity scenarios have been done to investigate the efficiency of water injection and consider the streamline-based simulation results for optimal water injectors optimization. This study has considered the cumulative oil production (NP) and net present value (NPV) as an objective functions to find out the optimal decision. In order to find the accurate attainment, the first future prediction scenario has been performed without water injection by running the black-oil reservoir model for future period production of 12 years. Then, full factorial design (FFD) considering water injection rates and number of water injectors as factors has been adopted. Twenty-five experiments have been carried out for the two factors with five levels. The full factorial design (FFD) results showed that the oil recovery is getting higher at the lowest levels of water injection rate and number of injectors; however, the injection rate has the highest effect. The optimal scenario has shown higher cumulative oil production when activate nine wells with 4000 STB/DAY. Never the less, the FFD has shown that the number of activated injectors has the highest influence when the NPV is the objective function and NPV has the highest value at the lowest water injectors. Consequently, the optimal scenario is either considering one injector with 2000 STB/DAY injection rate or to continue with base case of non-injection as there is very small difference in NPV. This optimal injector has connections with 15 producers and should support the reservoir pressure. The validity of the two linear models has been done by t-test, p-value, and F-Statistics & Analysis of Variance (ANOVA).

Introduction

An efficient design of integrated reservoir studies through economic analysis and statistical modeling is a unique way for optimal planning of future reservoir performance prediction. Improve and predict the future reservoir performance requires investigate the optimal ways to improve the oil production for long time. One of the considerable schemes is the water injection.
Rock Physics Modelling in Oil and Gas Field Development, A Methodology for Reservoir Characterisation below Shallow Gas
Authors: M Yusoff Yusma Bazleigh , Radzi Nor Afiqah , Khalil Ashraf , Amdan Amri , Hong Chong Weng , Zeb Jahan , Ting Jimmy
Published: May 2016

A large number of oil and gas fields in the Peninsular Malaysia basin are screened (masked) by shallow gas, resulting in wipe out zones of the underlying seismic amplitudes as well as push down and time delay (sag) of the structural closure of economical oil or gas fields. Such effects lead to significant uncertainties in resolving and mapping of the objective reservoir units below the shallow gas.

On these premises, 3D 4C Ocean Bottom Cable (OBC) seismic survey has been acquired and processed in one of the gas and oil fields in the Malay basin with the objective of resolving the multi-layered reservoir intervals through mode converted shear component data.

This paper will discuss the rock physics and properties model that has been developed as part of a 3D 4C PP-PS Joint Seismic Inversion project with the primary objective of delineating and characterizing the various reservoir intervals and depositional environments of the oil and gas accumulation, a first in Petronas Carigali experience in reservoir characterization. This paper focuses on synthesizing missing logs, log conditioning, seismic petrophysical evaluation, rock physics modeling, invasion correction and fluid substitution to the fullwaveform (P- and S-wave) and density logs to make ready for seismic inversion.

A total of 10 wells with 8 measured P- and S-wave logs are available for this study. The overall qualities of well logs were adequate for the purpose of this inversion project. These data have been used in the generation of rock physics models. The methodology applied was to construct a rock physics model that is consistent with the petrophysical analysis and the elastic properties as given by the conditioned well log data. The model was then applied everywhere to generate synthetic elastic logs and full offset synthetic seismograms that were then compared and matched to the recorded data respectively.

Introduction

Well log data are used to understand the relationship between the reservoir properties and subsurface seismic data. Since well log data provide constraints and calibration in the inversion workflow, their quality directly impact the confidence and the accuracy of the inversion results for quantitative interpretation and follow-on reservoir modeling. Well log quality and consistency are subjected to various factors like variation in tool measurements, borehole rugosity, borehole fluids, elapse time between drilling and logging, invasion of borehole fluids into the formations, alteration of the formation properties due to the presence of the borehole and/or borehole fluids, casing points, and missing data. Therefore, the primary goal in processing well log data is to minimize measurement related errors, generate and fill in the missing data, and to obtain consistent and accurate logs between all the wells.
Uncertainty Analysis Turns Failed Infill Well into an Economic Success
Authors: Ontowiryo M Bambang , Kurniawan Akbar , Sardinda Lalang Jati , Suderajat Suderajat , Priyantoro Jati , Prakoso Ambaria , Sadat Anwar
Published: May 2016

The M oil field is located offshore within the Malacca Strait PSC, Indonesia. Reservoirs are sandstones in the Lower Sihapas (LS) Formation. They have strong water drive, are under-saturated, low viscosity/high API oil, low GOR and high dip angle.

Oil production started in 1986. Current oil rates are 0.6 Mbopd from ten wells with commingled completions. The current recovery factor is over 50%.

Major challenges to further develop this field are high water cuts, and old surface facilities.

In December 2010, the M-10 well was drilled as an attic well. Unfortunately, the oil rate was far below than forecasted, as the six target sands were 42–53 ft deep to prognosis, and oil has already been swept to the offset wells. Only the A sand, and an untargeted Upper Sihapas Formation sand contained clear indications of oil. However, reservoir deliverability from the sands was low due to depleted reservoir pressure and low permeability.

In 2012, reservoir modeling using a geostatistical approach created 21 realizations to cover uncertainty in facies distribution, porosity, permeability and oil-water contact. We adopted three models to represent the P10, P50 and P90 cases. The three models are history-matched based on analysis of probability of OOIP distribution. These models and C//O log as additional data consistently indicated that the B and E sands in M-10 should have good amount of remaining oil, despite the negative indications from gas shows and logs. Nodal analysis showed no cross flow would occur if we commingled these sands with the existing perforation.

Based on these studies, we performed a simple workover operation.

After perforation, the oil rate increased to 280 BOPD and settled down to 200 BOPD. A combination of reservoir simulation, uncertainty analysis, C/O log and nodal analysis turned the M-10 well from zero to hero.

Introduction

The M field was discovered in 1981 and first oil flowed in 1986 from the Sihapas Formation. The reservoirs produce 42° API oil with low GOR. All wells produce commingled from multiple sands with Electric Submersible Pumps (ESP). The reservoir has strong water drive mechanism combined with gravity drainage that make reservoir have high recovery. Currently, over 50% of oil in place has been produced.
Innovative Integrated Approach for Real-Time Liquid Rate Estimation for ESP Wells Production Optimization and Field Production Reconciliation in the Sabriyah Digital Oil Field
Authors: Al-Ali Abeer Khalid , Al-Hamer Mohammad , Hasan Bashar A. , Singh Siddharth , Moricca Giuseppe
Published: May 2016

A reliable liquid rate estimation is critical for evaluation of well and pump performance in wells lifted using electric submersible pumps (ESPs). The estimation of reliable liquid rates is a challenging and complex task even in digital oilfields (DOFs), such as the integrated Kuwait Integrated Digital Field (KwIDF) project in the Sabriyah (SA) field in North Kuwait. The correct liquid rate estimation is necessary to identify the ESP operating point to extend the ESP run life, improve field uptime, and identify production optimization opportunities.

Different methodologies have been adopted to provide the most reliable virtual liquid rate estimation:Real-time rate measurement.Virtual rate estimation based on well modeling using iterations of wellhead pressure (WHP) and pressure drop across the pump.Virtual rate estimation based on a well gradient plot using iterations of WHP, water cut (WC), and gas/oil ratio (GOR).Empirical correlation (tubing head pressure [THP] vs. liquid rate) based on measured data during surface multirate production testing.

This paper describes the approach adopted in the KwIDF SA for the best estimation of the real-time liquid rate in each well. The daily production rate reconciliation approach used in the KwIDF SA field will be discussed as well.

Using this approach, better well surveillance was made possible and an 18% increase in field uptime (equivalent to a 4% increase in production recovery) was achieved. In addition, more effective proactive analysisand a more stringent decision-making process were implemented.

In conclusion, this innovative approach provided more value in terms of asset surveillance compared to that conventionally adopted within the industry.

Introduction

Oil companies sometimes struggle to obtain a produced liquid and oil volume measurement, which is a very important piece of information for reservoir and day-to-day well surveillance and optimization.

In many cases, reservoir and well surveillance relies on monthly back allocation. This type of process creates a time gap between the event and problem identification. In some cases, problems are not identified for months.

Currently, many systems are available that can provide both direct and indirect fluid rate measurements for produced liquid and oil rate evaluation, e.g., a multiphase flow meter [MPFM] combined with a WC meter. This paper describes the use of a combination of different solutions for accurate measurement of liquid and oil rate in real-time. It includes a MPFM, WC meter, and virtual measurement using well models in real time matched with the latest well surface production test available.

The KwIDF SA project has developed a robust approach for estimating the real-time liquid rate and has implemented the use of a WC meter for real-time WC evaluation.
A Decade of Experience with Multiphase Flow Meters
Authors: Al-Kadem Mohammad S. , Al Khelaiwi Faisal T. , Al Mashhad Ali S. , Al Dabbous Mohammad S. , Al Amri Meshal A.
Published: May 2016

Multiphase flow metering is considered one of the most essential technologies in well testing. Since the mid 1990's, Multiphase Flow Meters (MPFM) have evolved from a revolutionary new technology into a consolidated solution widely adopted by the major operators worldwide. This evolution has taken place thanks to the high quality of measurements, low operational cost and the capability of enabling remote monitoring of wells' performance with ease. The meters have proven to be durable for testing oil wells of Saudi Aramco's (SA) fields.

The installed MPFMs in Northern fields of Saudi Aramco have contributed effectively to enhancing the semi-real time measurements' quality as well as improving reservoir characterization. However, MPFMs are prone to mechanical and firmware failures. To keep the general health of the installed systems, various preventive and ad-hoc services are needed. The MPFM technology largely seems to be performing as expected and delivering high quality data. So far, 58% of the systems have been in service for more than 8 years and continuing to operate efficiently.

Thorough analysis of the routine maintenance and checkups conducted during the past 10 years revealed the following: The MPFMs Mean Time between Failure (MTBF) and Mean Time to Repair (MTTR) indicated that the MPFMs have been available 97% of the time.The use of a probabilistic approach (Monte-Carlo™ Simulation) to study the P10, P50 and P90 values of the maintained MPFMs indicated that the variance between these values is small, demonstrating the reliability of these equipment.The classification of the diverse types of problems faced while operating the MPFMs highlighted the dominant cause of failures and enabled the initiation of a surveillance and subsequent failure mitigation program. The latter program resulted in fewer failures and higher equipment efficiency.

This paper discusses the lessons learnt and experience gained from operating 168 MPFMs provided by different vendors in different environments during a 10-year period, along with the appropriate solutions that were implemented to mitigate the challenges faced and subsequently improve the efficiency and data quality of the MPFM.
Surfactant-Polumer Flooding in Hard Brines and High Temperature Reservoirs
Authors: Delbos Aline , Tabary Rene , Chevallier Eloise , Moreau Patrick
Published: May 2016

Chemical EOR is a common process to increase recovery in oil reservoirs but these techniques are limited today in the case of high temperature and hard brines, mainly due to high adsorption issues and thermal stability of the chemicals. Specific formulations of surfactant and/or surfactant-polymer have to be designed and injection strategy has to be adapted for these challenging cases.

In this paper we first investigate the evolution of surfactant phase behavior in high temperatures and high hardness conditions and the way surfactant formulations can be adapted to these conditions. Specific chemicals are required to withstand challenging environment, specifically high temperatures. Adapted lab protocols are also required including essentially anaerobic conditions. We demonstrate how properly selected chemicals can be successfully blended and adapted injection strategies designed in these conditions.

We then present at the lab scale the effect of temperature and brine composition on surfactant adsorption through oil recovery coreflood experiments. In addition, we show the way adsorption is reduced in the case of hard brines, by the use of a salinity gradient. In these cases, the optimization of the injection strategy can help reduce the surfactant loss. High oil recoveries together with moderate surfactant adsorption can then be achieved opening new opportunities for development of chemical EOR.

1. Background information

Surfactant-Polymer (SP) and Alkaline-Surfactant-Polymer (ASP) have been acknowledged for decades to be among the most promising techniques to enhance oil production and reserves in mature oil fields. These processes consist in the injection into a formation of chemical slugs composed of surfactants, polymer and in some cases alkali [1; 2].

Surfactants are used to decrease interfacial tension (IFT) leading to an additional mobilization of oil initially trapped by capillary forces in the rock matrix [1]. Polymers are used in order to improve mobility control and sweeping efficiency [1; 2]. The addition of alkali leads to a decrease of surfactant adsorption onto reservoir rock, specifically in presence of clays. Additionally, for reactive oils, alkali leads to the in-situ generation of soaps induced by the saponification of acidic crude oil components [3] improving overall process performances.

Most published successful studies so far focus on relatively favourable reservoir conditions. Under more challenging conditions, performance of ASP/SP flooding can drastically decrease [4]. Among specific hurdles, high salinity/hardness and/or high temperature make ASP/SP processes challenging, both at laboratory and field scale.
Integrating High-Resolution Multiwell Image Logs to Improve Geological Reservoir Characterization and Sequence Stratigraphy
Authors: Bahadidah Taleb Ahmed , Dashti Rouhollah , Ismail Mohammed Fauzi , Nair Nisha , Marca Sandra , Abd Malek Alya , M. Yunan M. Izzat Fauzi , Johansson Melissa
Published: May 2016

A high-resolution multiwell geological reservoir characterization and integration study was conducted using subsurface data, including high-resolution images from an oil-base microimager, conventional openhole logs (including gamma ray, neutron, density, and resistivity), cores, mud logs, and 3D seismic data from eight wells. The study was performed on a shallow-water clastic reservoir to analyze the structural dip, reservoir facies, paleocurrent, and overall depositional settings. Ultimately, a sequence stratigraphy procedure was implemented to divide the entire studied interval into a certain number of genetically related stratigraphic packages, which were subsequently correlated with the regional stratigraphic markers in that basin.

Scope and Objectives

The studied field is one anticline structure separated by major bounding faults. This field is located offshore and is a major gas producer. The main producing targets are early to middle Miocene sands. The wells in this study are placed along the fold axis of the field from southwest to northeast, providing a good coverage of the entire area. Therefore, the wells in this study, named A through H for confidentiality reasons, are arranged in cross section from southwest to northeast in the following order: well H, well G, well F, well E, well D, well B, and well A (Figure 1).

The main objectives of this analysis are1.Developing an integrated study to evaluate and extract structural, paleocurrent and depositional characteristics of the main reservoirs in the field.2.Updating the existing well tops, which were provided by the operator, using the newly generated true stratigraphic thickness (TST) index.3.Validating and fine-tuning the existing model using smaller-scale data -images logs- with higher resolution than seismic.4.Resolving some field ambiguities such as pressure discontinuity and formulating solid guidelines for future field development plans
Biology and management of fruit borer, Virachola isocrates (Fab.) Infesting guava
Authors: Khan MMH
Published: May 2016

Two experiments were conducted to study the biology of guava fruit borer, Virachola isocrates (Fab.) and to evaluate the effectiveness of management practices for managing fruit borer, Virachola isocrates (Fab.) in Sharupkathi variety of guava. The biology including morphometrics of guava fruit borer were studied in the laboratory of the Department of Entomology, PSTU, Dumki, Patuakhali during May to October, 2012. Results revealed that incubation period, larval period, pupal period of this borer ranged from 8-10, 17-46, 7-33 days, respectively and total life cycle was completed within 30 to 60 days. Adult longevity ranged from 4-7 days. The average length of full grown larva was 17.45 mm, and breadth across thorax and abdomen were 3.36 and 2.80 mm, respectively. The average length of pupa was 15.90 mm, and breadth across thorax and abdomen were 3.68 and 2.89 mm, respectively. The average length of adult body was 16.90 mm, and breadth across thorax and abdomen were 3.91 and 2.94 mm, respectively. The average length of antennae was 10.35 mm. The mean length of pro-, meso and metathoracic legs was 7.55mm, 8.10mm and 10.45 mm, respectively. The metathoracic leg was longer as compared to pro and mesothorarcic legs. The length of fore wing across the upper and lower margin ranged from 16.00 mm to 18.00 mm and 11.50 mm to 12.00 mm, respectively. The length of hind wing across the upper and lower margin ranged from 10.00 mm to 11.00 mm and 8.00 mm to 9.00 mm, respectively. The breadth of fore wing across the middle ranged from 10.50-11.00 with mean breadth of 10.78 mm. Likewise, the breadth of hind wing across the middle ranged from 11.00-14.00 with mean breadth of 12.55 mm. The results on the percent infestation reduction over control revealed that package with field sanitation + collection of infested fruits + application of Superior (Chlorpyrifos + Cypermethrin) 505 EC @ 1 ml/ l water, and package consisting of field sanitation + collection of infested fruits + bagging of fruits with polythene bag gave 100 % control of the pest. These two packages may be used for the large scale cultivation of Sharupkathi variety in BangladeshBangladesh J. Agril. Res. 41(1): 41-51, March 2016
In vitro conservation of taro (Colocasia esculenta Var. Globulifera) as influenced by mannitol
Authors: Bhuiyan MKR , Hossain MJ , Haque MM
Published: May 2016

In vitro conservation of germplasm plays a vital role in maintenance breeding and also has many advantages over the conventional system. The experimental results for conservation of Colocasia sp. also proved this. In relation to explants and osmoticum, meristem and axillary bud could be conserved for 24 months while meristem-base died after 6 months. Mannitol as osmoticum @ 4% performed nicely to conserve Colocasia upto 24 months. Only meristem and axillary bud could be conserved for 24 months with the use of 4 % mannitol. But other level of mannitol remained culture alive for varying periods (6 to 12 months). After 24 months, the plant height was 6.5 cm for the meristem and 6.4 for axillary bud.Bangladesh J. Agril. Res. 41(1): 67-74, March 2016
Effect of flooding on growth and yield of mungbean genotypes
Authors: Amin MR , Karim MA , Islam MR , Aktar S , Hossain MA
Published: May 2016

The field experiment was carried out with some selected mungbean genotypes viz. IPSA-13, VC-6173A, BU mug 2, BARI Mung-5 and IPSA-12 to observe the effect of 4-days flooding on their growth and yield of mungbean under field conditions at Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh during September to November, 2011 maintaining 3-5 cm standing water at 24 days after emergence. Days to flowering and maturity delayed in flooded plants over control depending on the genotypes. Flooding significantly reduced Total Day Matters (TDM), number of pods per plant, seed size and seed yield of the mungbean genotypes over control. Considering higher seed yield, larger seed size and less yield reduction relative to control VC-6173A, BU mug 2 and IPSA-13 were found tolerant to soil flooding condition.Bangladesh J. Agril. Res. 41(1): 151-162, March 2016
Prevalence of ovine footrot in Brahmaputra Chars (shoals) in Mymensingh
Authors: Haq MM , Rahman MM , Rana S , Khatun M , Samaddar K
Published: May 2016

A retrospective cohort study was conducted from July 2012 to August 2013 to determine prevalence of ovine footrot in chars (Shoals) of Mymensingh Sadar Upazila, Bangladesh, centred in Paranganj Union Parishad. A field survey used a prepared questionnaire and investigation of farm management. The prevalence of ovine footrot was 4.2% in the study group of 687 sheep, in 106 farms. The prevalence differed according to farm type and housing system. Prevalence of ovine footrot was higher (9.5%) in farms where sheep and other livestock were housed under the same roof. Prophylactic medication and footbath practice were absent. Common care and management practices were sheep bath, house and floor cleaning, deworming, and therapeutic medication. Highest prevalence (7.0%) was recorded in farms where prophylactic medication and deworming was irregular, and antiseptics were not used in sheep bathing and cleaning of sheep house and floor. The results suggest that improvement of the housing environment and management practices are required to control footrot.Bangl. vet. 2014. Vol. 31, No. 2, 74-83
Global Responsibility and the Enhancement of Life
Authors: Schweiker William
Published: May 2016

This article advances a conception of global ethics in terms of the centrality of responsibility to the moral life and also the moral good of the enhancement of life. In contrast to some forms of global ethics, the article also seeks to warrant the use of religious sources in developing such an ethics. Specifically, the article seeks to demonstrate the greater adequacy of a global ethics of responsibility for the enhancement of life against rival conceptions developed in terms of Human Rights discourse or the so-called Capabilities Approach. The article ends with a conception of ‘conscience’ as the mode of human moral being and the experience of religious transcendence within the domains of human social and historical life. From this idea, conscience is specified a human right and capacity to determine the humane use of religious resources and also the norm for the rejection of inhumane expressions of religion within global ethics.
Impact of Androstenone on Leash Pulling and Jumping Up in Dogs
Authors: Pirner Glenna , McGlone John
Published: May 2016

Dogs are relinquished to shelters due to behavioral problems, such as leash pulling and jumping up. Interomones are chemical cues produced by one species that elicit a response in a different species. We reported earlier that androstenone, a swine sex pheromone, acts as an interomone to reduce barking in dogs. Here we report two models using 10 dogs/study: a dog jumping and a dog walking model. For the leash-pulling model, each time the dog pulled on the leash the walker either did nothing (NOT), or sprayed the dog with water (H2O), androstenone + water (ANH), androstenone 0.1 µg/mL (AND1), or androstenone 1.0 µg/mL (AND2). The number of pulls during each walk was counted. For the jumping up model, each time the dog jumped the researcher did nothing (NOT), or sprayed the dog with H2O, ANH, AND1, or AND2. The number of jumps and the time between jumps were recorded. In Study 1, ANH, AND1, and AND2 each reduced leash pulling more than NOT and H2O (p< 0.01). In Study 2, all treatments were effective in reducing jumping up behavior. Androstenone reduced jumping up, but not beyond that elicited by a spray of water alone. We conclude that androstenone in multiple delivery vehicles reduced leash pulling. The burst of air intended as a disruptive stimulus in the correction sprays may be too harsh for more sensitive dogs, and as such use of these sprays is cautioned in these animals. For other dogs, this interomone can be used to stop some behavior immediately or as a part of a training program to reduce undesirable behavior.
A Review of Systems and Technologies for Smart Homes and Smart Grids
Authors: Lobaccaro Gabriele , Carlucci Salvatore , Löfström Erica
Published: May 2016

In the actual era of smart homes and smart grids, advanced technological systems that allow the automation of domestic tasks are developing rapidly. There are numerous technologies and applications that can be installed in smart homes today. They enable communication between home appliances and users, and enhance home appliances’ automation, monitoring and remote control capabilities. This review article, by introducing the concept of the smart home and the advent of the smart grid, investigates technologies for smart homes. The technical descriptions of the systems are presented and point out advantages and disadvantages of each technology and product today available on the market. Barriers, challenges, benefits and future trends regarding the technologies and the role of users have also been discussed.
Origin of Petrified Wood Color
Authors: Mustoe George , Acosta Marisa
Published: May 2016

Fossil forests have world-wide distribution, commonly preserving mineralized wood that displays vivid hues and complex color patterns. However, the origin of petrified color has received little scientific attention. Color of silicified wood may be influenced by the presence of relict organic matter, but the most significant contribution comes from trace metals. This study reports quantitative analysis of trace metals in 35 silicified wood samples, determined using LA-ICP-MS spectrometry. The most important of these metals is Fe, which can produce a rainbow of hues depending on its abundance and oxidation state. Cr is the dominant colorant for bright green fossil wood from Arizona, USA and Zimbabwe, Africa. Complex color patterns result from the progressive nature of the fossilization process, which causes wood to have varying degrees of permeability during successive episodes of permineralization. These processes include simple diffusion, chromatographic separation, infiltration of groundwater along fractures and void spaces, and oxidation/reduction.
Comparing One-Way and Two-Way Coupled Hydrometeorological Forecasting Systems for Flood Forecasting in the Mediterranean Region
Authors: Givati Amir , Gochis David , Rummler Thomas , Kunstmann Harald
Published: May 2016

A pair of hydro-meteorological modeling systems were calibrated and evaluated for the Ayalon basin in central Israel to assess the advantages and limitations of one-way versus two-way coupled modeling systems for flood prediction. The models used included the Hydrological Engineering Center-Hydrological Modeling System (HEC-HMS) model and the Weather Research and Forecasting (WRF) Hydro modeling system. The models were forced by observed, interpolated precipitation from rain-gauges within the basin, and with modeled precipitation from the WRF atmospheric model. Detailed calibration and evaluation was carried out for two major winter storms in January and December 2013. Then, both modeling systems were executed and evaluated in an operational mode for the full 2014/2015 rainy season. Outputs from these simulations were compared to observed measurements from the hydrometric station at the Ayalon basin outlet. Various statistical metrics were employed to quantify and analyze the results: correlation, Root Mean Square Error (RMSE) and the Nash–Sutcliffe (NS) efficiency coefficient. Foremost, the results presented in this study highlight the sensitivity of hydrological responses to different sources of simulated and observed precipitation data, and demonstrate improvement, although not significant, at the Hydrological response, like simulated hydrographs. With observed precipitation data both calibrated models closely simulated the observed hydrographs. The two-way coupled WRF/WRF-Hydro modeling system produced improved both the precipitation and hydrological simulations as compared to the one-way WRF simulations. Findings from this study, as well as previous studies, suggest that the use of two-way atmospheric-hydrological coupling has the potential to improve precipitation and, therefore, hydrological forecasts for early flood warning applications. However, more research needed in order to better understand the land-atmosphere coupling mechanisms driving hydrometeorological processes on a wider variety precipitation and terrestrial hydrologic systems.