bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Crop Volume on Contraction Rate in Adult House Fly
Authors: Stoffolano John G , Patel Bhavi , Tran Lynn
Published: June 2014

The functional aspects of the adult house fly crop have not been studied even though various human and domestic animal pathogens have been discovered within the crop lumen. The average volume consumed (midgut and crop) by flies starved for 24 h was 3.88 µl by feeding both sexes on a sucrose phosphate glutamate buffer. In addition, various volumes of a solution (0.125 M sucrose plus Amaranth dye) were fed to 3-d-old adult female house flies to quantify the crop contraction rate as affected by crop volume. As crop volume increased, the contraction rate increased until it reached a peak at 2 µl, after which it declined. It is hypothesized that the high contraction rate of the crop, which in house fly is almost twice the rate of three other fly species, is one of the factors that makes house fly an excellent vector. The mechanism for such a high contraction rate needs to be investigated.
Relations among electrical resistivity, chemical and autogenous shrinkage of cement pastes
Authors: Zuo Yibing , Wei Xiaosheng
Published: June 2014

Electrical resistivity, chemical shrinkage and autogenous shrinkage were measured for cement pastes with different water to binder (w/b) ratios (0·30, 0·35 and 0·40) and fly ash replacements of cement (0%, 30% and 50%). The electrical resistivity, chemical shrinkage and autogenous shrinkage of the pastes decreased with increasing w/b ratio and fly ash content after final setting. The autogenous shrinkage development over time could be divided into a setting period, a rapid growth period, an expansion period and a slow growth period. Based on the test results, the chemical shrinkage and the autogenous shrinkage were linearly correlated to electrical resistivity after hydration for 24 h and 30 h respectively. The linear relationships will help to expand the application of electrical resistivity measurements. The parameter γ, defined as the proportion of autogenous shrinkage to linear chemical shrinkage after the final set, decreased with time due to increasing paste stiffness. This parameter will help researchers quantitatively understand the volume proportion of autogenous shrinkage and empty cavities during hydration.
Optimisation of shear strengthened reinforced concrete beams
Authors: Yapa Hiran D. , Lees Janet M.
Published: June 2014

External prestressed carbon fibre reinforced polymer straps can be used to strengthen shear-deficient reinforced concrete structures. For an efficient shear retrofitting system, the optimum combinations of parameters such as the number of straps, strap locations, strap stiffness and initial strap prestress need to be identified. The modified compression field theory and the shear friction theory have previously been applied to carbon fibre reinforced polymer strap strengthened beams. As implemented, both of these methods are iterative. Particle swarm optimisation and genetic algorithm stochastic optimisation methods were used to reduce the computational cost associated with the shear strength evaluation and also to search the design space for carbon fibre reinforced polymer strap strengthened beams. An initial comparison across several test functions showed that the preferred optimisation algorithm depended on the characteristics of the design space. When applied to a reinforced concrete case study, the genetic algorithm was better for searching the shear friction theory shear strength design space that was characterised by several peaks. However, for the smoother modified compression field theory shear strength evaluation space, and for the design space for the carbon fibre reinforced polymer strengthened beams calculated using either the modified compression field theory or the shear friction theory, the particle swarm optimisation converged more quickly and accurately. The optimised solutions reflect the assumptions within the underlying evaluation methods.
Frugivores at higher risk of extinction are the key elements of a mutualistic network
Authors: Vidal Mariana M. , Hasui Erica , Pizo Marco A. , Tamashiro Jorge Y. , Silva Wesley R. , Guimarães Paulo R.
Published: June 2014

Most tree species rely on vertebrates for seed dispersal, and many vertebrates use fruits as food resources in tropical forests. Therefore, plant–frugivore interactions affect population dynamics and persistence in ecological communities. Plant–frugivore interactions often involve many species, forming networks of interacting plants and animals that play different roles in determining network organization. The network organization is the way interactions are structured in the community, which may have consequences for its ecological and evolutionary dynamics. Some species have greater influences on network organization and may be particularly important to species persistence. We identified the frugivores most important to the organization of networks of plants and frugivorous birds in three contiguous Atlantic forest sites in southeastern Brazil. We found that the species that contributed most to network organization were at higher risk of extinction. Among the main contributors to network organization were two cotingas and a toucan, large‐bodied species that disperse seeds from many plants and are particularly vulnerable to habitat loss and hunting. As a consequence, ongoing extinctions may significantly affect the organization of plant–frugivore interactions in the studied system. We hypothesize that the crucial role of some threatened frugivores may occur in other seed dispersal systems in tropical communities, although the association between structural importance and degree of threat may be contingent on peculiarities of local communities and disturbances.
The Interacting Body: Intra- and Interindividual Processes During Imitation
Authors: Nadel Jacqueline , Dumas Guillaume
Published: June 2014

Cognition involving others, or social cognition, is often conceptualized as the solitary, third-person computation of mental states. Relatively, little attention has been paid to how individuals use their cognitive capacities at the behavioral and brain levels in social exchanges. We introduce imitation as a valuable model of dynamic social interactive phenomena and describe laboratory procedures for studying it in behavioral and neuroimaging contexts. We review research that reveals behavioral and neural synchronization of individuals engaged in imitation. In the latter case, brain activity is correlated in imitative partners, but the pattern expressed by an individual depends on the individual’s role (i.e., model or imitator). We link these findings to theoretical notions about mirroring and mentalizing brain systems and then describe how mirroring and mentalizing support the notion of prospective cognition, even in basic forms of communication such as reciprocal imitation.
The Development of Children’s Understanding of Maps and Models: A Prospective Cognition Perspective
Authors: Uttal David H. , Sheehan Kelly J.
Published: June 2014

This article takes a prospective cognition perspective in reviewing research on the development of children’s understanding of spatial symbols, such as scale models and maps. We suggest that using spatial symbols requires that children think about where an object will be found rather than where they last saw it. In addition, we suggest that as children’s knowledge of maps grows, they begin to think about large-scale space through the mediated perspective that maps provide.

Maps allow people to see and to think about multiple relations among locations, as well as spaces that are much larger than can be directly perceived. Learning about the world through maps is a good example of what Tomasello (1999) called the cultural ratchet effect; each generation can rely on information from prior generations rather than having to learn or discover it on their own. Thus, cultures share views of space through maps, and the development of the cognition of large-scale space consists in part of learning to think about the world through maps.
Anticipation and Embodied Knowledge: Observations of Enculturating Bodies
Authors: Hahn Tomie , Jordan J. Scott
Published: June 2014

This article represents a collaborative integration of ethnographic techniques and cognitive neuroscience for examining the dynamics of the movement pedagogy that takes place within Japanese traditional dance. The goal is to examine the extent to which the notion of multiscale entrainment, a hallmark assumption of prospective cognition, can enhance our understanding of the movement pedagogy dynamics that emerge during a given pedagogical session and the larger timescale events that come to be learned over sessions (e.g., the student–teacher relationship, the multiple sessions needed to learn an entire dance, and the annual events associated with Japanese dance pedagogy). The analysis will examine the extent to which Japanese dance pedagogy entails embodied anticipation (i.e., movement learning that gives rise to later movement anticipation) and multiscale embodied anticipation (i.e., multiscale events that come to be recursively associated with movement planning and, as a result, appear in one’s later movement planning). In addition, we analyze the extent to which the Japanese dance studio can be conceptualized as an external scaffold that affords (a) a space for student–teacher interactions, (b) the long-term maintenance of a historical–cultural tradition, and (c) the pedagogically driven emergence of a rich phenomenal sense of belonging to something larger than the timescale of one’s immediate movement planning.
Foamdrive Seldom Meaningful
Authors: Dietz D.N. , Bruining J. , Heijna H.B.
Published: June 2014

With the present interest in foamdrive, there is an increasing need for aproper definition and description of "foam." A sample of foam isrepresentative of foam and its bulk properties only if it has sufficient size. To take an extreme, a microscopic sample out of the middle of a gas bubble isnot "foam." Bulk properties such as gas content, viscosity, etc., canbe determined only on samples sufficiently large to contain many bubbles, counted in all three dimensions. Foam properties are relevant only with respectto samples over some minimum size, and this size is related directly to bubblesize.

Discussion

Some direct measurements of bubble size from photographs in the literaturegave diameters of about 200 micron. We also have estimated the theoreticalminimum bubble size.

In a flow experiment, of course, we can observe foam before it enters a coreand we may see foam being formed where gas and liquid leave a core. Within theporous rock there is two-phase flow, but there is seldom reason to believe thatthis flow can be described by a quasi singlephase flow of a "foam" showing the same viscous behavior as measured macroscopically outside the rock.

Conclusions

Where authors claim that a so-called foamdrive yields a higher oil recoverythan normal two-phase flow, we may have to find another explanation. Althoughthe mechanical structure of foam may break down upon entrance into a porousmedium, the chemical composition still differs from a conventional gas/watercombination through the presence of surface-active agents.
Efficient Open-Hole Logging of the Horizontal Wells Using Openhole Tractoring. Field Experiences from TATWEER Petroleum Company-Bahrain
Authors: Ofield Bill , Down Michael , Al-Hashimi Lana , Hermes Amir , Murphy Nicolas , Hamdy Mohamed , Eissa Moustafa , Annovi Enrico
Published: June 2014

Horizontal drilling is fast becoming an effective economical solution to maximize the asset value for E & P companies. Since established in 2009, TATWEER petroleum is one of those companies that utilize horizontal drilling intensively to improve the production and the recovery factor from tight and fractured carbonate reservoirs within the Bahrain Field.

Reservoir complexity and heterogonity create the need for running open-hole logs in most of the horizontal wells within the Bahrain field. Logging is essential for the following: Designing the well completion (Open hole or Slotted liner equipped with external packers), predicting and understanding the well performance, and planning future work-over activities (Water and Gas Shutoff).

Normal practice to deploy open hole logging tools into the HZ horizontal section within the Bahrain field was to use drill pipe (Tough Logging Conveyance). Given the typical low productivity of wells, operational costs were of concern. Consequently, TATWEER requested alternative methods to optimize the logging operations in horizontal wells.

Of the options offered by Schlumberger, tractoring technology was deemed to be best. The main challenge faced initially was with tractoring in the low uniaxial compressive strength (UCS) of the reservoir formations (UCS=1400-3000 PSI) in Bahrain. Since tractoring is known to be an effective deployment method for hard formations (UCS>5000 PSI), the new OH tractoring technology (UltraTRAC*) was offered by Schlumberger as a solution for this low UCS enviroment.

UltraTRAC* was successfully deployed in TATWEER wells, saving 60-70% of the logging time comparing to the normal TLC (Tough Logging Conveyance) operations which represents 5% saving of the total well cost.

In this paper, the authors discuss the details of this new logging methodology, logging results, and value obtained from using this technology.
Statistical Approach to Forecasting Fluid Loss Solutions
Authors: Alexeyenko A. V.
Published: June 2014

Increasing efficiency and safety of drilling operations requires proactive planning and ability to make timely educated decisions. Evaluating operational experience and statistically organizing available drilling data provide valuable forecasting tools, which help to increase the rate of successful decisions. For this paper, drilling records from 54 recent wells drilled by Saudi Aramco exploration unit throughout 2009-2011 period, both offshore and onshore, were evaluated. Large volume of statistical data related to drilling fluid losses was systemized. Losses were tagged as partial and total losses for each well and hole size. Drilling fluid daily reports provided insight into volume and cost of losses for drilled hole sections. Fluid losses cost per foot and lost time cost per hour was calculated. Cost per foot of LCM and cost per foot of other fluid loss preventive techniques and technologies was estimated, as well. This data analyses led to the capability of benchmarking expected losses cost per foot against expected cost per foot of available fluid loss fighting or preventive materials and services. Obtained numbers provide straight forward decisive data to plan for cost effective solution using a decision flowchart. Available statistical and risk evaluation software adds to the decision process effectiveness. This paper does not cover all available or would be available loss prevention techniques and technologies. The discussed method was applied in real life, and aerated drilling fluid services are contracted for Saudi Aramco drilling operations.
Exploration Drilling Performance Optimization in Red Sea Shallow Water: Shifting West with Offshore Exploration Drilling Best Practices
Authors: Khalifa Saleh , Azzouni Suliman , Tiwari Shrikant , Adewuya Opeyemi
Published: June 2014

Exploration drilling activities are not endeavors that afford optimization given the variability of the drilling environment and inherent uncertainty of the lateral discontinuous geology. The ongoing exploration drilling program comprising several wells and various wellsites in the shallow waters of the Red Sea is providing an opportunity to progressively refine exploration drilling practices, and extract incremental efficiencies while maintaining a zero saftey incident record.

The Saudi Aramco shallow water exploration drilling program is targeting a transition zone corridor approximately 10-30 km wide in shallow to moderately deepwater straddling the coastline at the northwestern end of the Red Sea. Given the proximity of the Burqan and Midyan fields, geological and stratigraphic analyses are developed using analogues from extensively studied geophysical and geomechanical models.

Initial well designs developed from the basis of design anticipated extensive salt sections and moderately divergent geopressure beginning in the rubble zone and extending beyond the Kial formation. After drilling two successful exploration wells, learnings from solutions developed to address drilling challenges are presented.

Optimization of the casing design afforded by the use of large bore logging while drilling (LWD) tools is complemented by a bottom-hole assembly (BHA) reconfiguration based on results of a BHA dynamics study. The high temperature profile of the wells drilled also presented another dimension to the challenge as well the opportunity to test emerging high pressure, high temperature (HPHT) logging technology. The pore-pressure fracture gradient (PPFG) profile emulating a post-salt abnormally geopressured trend and strike-slip stress regime initially elicited the use of seismic while drilling technology to resolve poor imaging difficulties below the salt but subsequently discontinued to determine the best lookahead strategy and job design.

Ensuring environmental stewardship required careful planning for the disposal of waste from drilling cuttings. For the frontier area in the Saudi Arabian Red Sea, the extensive environmental impact assessment and measures to ensure compliance with national and corporate environmental policy is also presented.
Bottom-Hole Assembly Management System (BHAMS)
Authors: Alotaibi Bader , Contreras Otalvora William B. , Nefai Mohammad S.
Published: June 2014

The bottom-hole assembly (BHA) is one of the most critical downhole drilling string components that determines the course of the drilling operation and its efficiency. It provides the required force on the bit (weight on bit) to efficiently penetrate formations; it facilitates acquiring operational data to successfully land wells; and enables directional drilling. The BHA also affects the borehole shape, direction and other geometric characteristics. In addition, it plays a significant role in determining the rate of penetration (ROP) leading to faster and more efficient drilling or otherwise that could translate to significant cost optimization (or, alternatively, waste). Drilling troubles such as stuck pipes, wellbore stability, cleaning and nonproductive time (NPT) is another area impacted by how optimized the BHA is leading to client satisfaction and timely achievement of objectives in a cost effective manner.

To achieve optimal BHA design, engineers and professionals need intuitive access to historical BHA data to perform in-depth analysis studies and correlate drilling troubles with used BHA designs, which allow them to develop the required mitigation plans and improve the BHA designs for wells. Moreover, this will contribute to a well's hydraulics optimization by linking BHA data with the real-time data.

In this paper, Saudi Aramco shares its experience in constructing a computer software system that facilitates capturing, tracking and analyzing complex BHA data in a more structured manner. The paper demonstrates how the system ensures the integrity of BHA data by applying business rules and data quality controls.
Investigating Formation Water Salinity Using a Unique Water Extraction Technique in a Hydraulically Active Area
Authors: Forsyth D. , Witjaksono M. , Palmer R. , Silva A. , Najrani Hussain , Zeghlache Mohamed L. , Mitchell P.
Published: June 2014

The main Permian Reservoirs in Central Saudi Arabia have presented an evaluation challenge because of the presence of fresh-brackish water encountered directly below the hydrocarbon accumulations. If this water is used in the evaluation of the oil zone then high connate water saturation is obtained which is inconsistent with generally initial water free oil production observed in the field. Early field development evaluation pragmatism assumed a dual salinity model. Higher salinity formation water was used for the evaluation of the oil zone and fresher water used for evaluation of the underlying water zone. The oil zone formation water was assumed to be the original depositional water present at the time of oil migration. High salinity can be typical for an Arid Fluvial-Estuarine system with high evaporation. Oil migration trapped this water in place. Post-hydrocarbon migration, Paleozoic rain water from higher elevations of the Arabian Shield recharged and flushed the original water beneath the oil. Practical issues have limited confirmation of this assumption and no measurements have been taken to confirm the oil zone water salinity or the dual salinity model.

A new technique is being explored that involves extraction and analysis of small quantities of fluid from core plugs sampled at the rig site. Invasion is quantified using mud doping. Initial results show that there is indeed evidence for higher salinity water present in the hydrocarbon zone compared with fresher water in the aquifer, consistent with the proposed dual salinity model. Extended testing of the technique has been conducted which shows that it can be used to measure water salinities in even very tight rock (~micro Darcy). The potential of the technique is to provide a more reliable fluid discriminator, both in these low relief difficult to evaluate formations, and in exploration and unconventional areas.
Case Study: Application of Azimuthal Resistivity, Azimuthal Density, and Resistivity Inversion to Geosteer in a Clastic Stringer, Saudi Arabia
Authors: Saint Craig , Martakov Sergey , Mumtaz Asim , Al-Dhaferi Yousef , Al-Khaldi Nasser , Sinha Sashi , Al-Sultan Athbi
Published: June 2014

Geosteering within thin clastic reservoirs can be extremely difficult due to their varying thicknesses, lateral facies changes and changing channel geometry. The efficiency of traditional triple-combo tools does not help achieve this objective due to their lack of azimuthal sensitivity. This paper presents a case history of reservoir navigation within a clastic reservoir in Saudi Arabia utilizing deep azimuthal resistivity, reservoir navigation modeling, and multi-component while drilling (MCWD) resistivity inversion.

A number of challenges needed to be overcome for this well to become a successful oil producer. Firstly, the development and lateral continuity of the reservoir sand was not guaranteed. Reservoir sand developed at the bottom of the formation in all nearby offset wells. The development in the upper part of the target formation however, varied throughout the field. In addition, further uncertainty was present regarding position of the oil-water contact (OWC).

A reservoir navigation strategy was devised utilizing a full triple combination of logging while drilling (LWD) tools that included deep azimuthal resistivity and azimuthal density. In addition, MCWD resistivity inversion software was used to ascertain the resistivity of the shoulder beds through inversion of real-time resistivity and azimuthal resistivity curves. The reservoir navigation strategy comprised maintaining a well inclination of 85 degrees until a clean reservoir sand was penetrated. MCWD would provide the first indication of the approaching reservoir, and well inclination would be increased in anticipation of reservoir entry. Upon entry in the reservoir, the deep azimuthal resistivity data, used in conjunction with reservoir navigation, would keep the well in the reservoir until TD or until the sand pinched out. In addition, MCWD would be used to ascertain the lower conductive boundary resistivity, either shale or water.

This strategy was successfully implemented and resulted in 1,400 ft of reservoir contact, achieving 100% Net: Gross. The deep azimuthal resistivity prevented reservoir exit in spite of higher-than-anticipated formation dip and a thinning reservoir towards the toe of the well. MCWD successfully proved that the lower conductive boundary was shale, not water, and confirmed the distance to the boundary results from the deep azimuthal resistivity tool.
High-Performance EOR System in Carbonate Reservoirs
Authors: Abdelgawad K. Z. , Mahmoud M. A.
Published: June 2014

With the increasing activities in the oil industry more interest is paid to the enhanced oil recovery (EOR). EOR is the area of increasing the producible oil from oil reservoirs. Recently, sea water has been used as a new EOR fluid by tuning its salt content to decrease its salinity and the new water was called low salinity (LowSal) water or smart water. This lead to studying the effect of LowSal water flooding on the recovery factor from oil reservoir due to the thought that LowSal water will interact with the rock surface either by multiple ion exchange or dissolution. Most of the research done confirmed that the presence of anhydrite in the rock is a must for an effective LowSal water flooding as the sulphate ions acts as a catalyst in the rock/fluids interaction.

In this study, we will introduce a new chemical EOR method that can be implied in carbonate reservoirs. The new method employed the ability of chelating agent (High pH EDTA, HEDTA) to sequester metal ions in solution and prevent also any solid precipitates in the reservoir. The widely available sea water will be used without any desulphonation processes since there will be no tendency to interact with the formation brine. Coreflooding experiments were performed using carbonate core outcrops at high temperature and different chelating agents' forms and concentrations were used in the flooding process.

The results of the coreflooding experiments showed that up to 20% of the original oil in place (OOIP) can be produced by injecting about six pore volumes of 5 wt% chelating-agent/sea water solutions. The increased recovery can be attributed to the dissolution of the carbonate rock surface and liberation of the oil attached to it and in the same time a reduction in the IFT due to the high pH injected fluid (pH=13).
CO2 Minimum Miscible Pressure MMP Estimation using Multiple Linear Regression MLR Technique
Authors: Alomair Osamah , Iqbal Maqsood
Published: June 2014

Miscible gas injection processes are among the effective methods for enhanced oil recovery (EOR). A key parameter in the design of gas injection project is the minimum miscibility pressure (MMP), whereas local displacement efficiency from gas injection is highly dependent on the MMP. Because experimental determination of MMP is very expensive and timeconsuming, searching for fast and robust mathematical determination of gas-oil MMP is usually wished. A new CO2 MMP correlation based on Multiple-Linear-Regression modeling (MLR) technique has been successfully developed to more accurately estimate the CO2 MMP for a wide range of live and heavy crude oils. The newly developed CO2 MMP correlation is originated from CO2 MMP experimental data in addition to database from the worldwide published literature that covers 103 pure CO2 MMP data for various live and dead oil samples. The proposed model is trained by exploiting 80% (82 data points) of the data bank. This correlation is expressed as a function of reservoir temperature, C7+ molecular weight, mole fractions of; non-hydrocarbon components (CO2, H2S and N2), direct correlating components (C1, C2 and C5) and indirect correlating components (C3, C4, C6 and C7). Further, to investigate the authenticity in depth, the proposed correlation is compared with five most commonly used pure CO2 MMP correlations from the literature. A statistical comparison is performed for both training data set (82 data points) as well as testing data set (21 data points). It is found that the proposed CO2 MMP correlation provides the best reproduction of MMP data with a percentage average absolute error of 6.083% and 6.328% for training and testing categories respectively. Finally, the proposed model shows great performance using new set of samples compared with other correlations.
Foamability and Foam Stability of Several Surfactants Solutions: The Role of Screening and Flooding
Authors: Belhaij Azmi , AlQuraishi Abdulrahman , Al-Mahdy Osama
Published: June 2014

Foamability and foam stability are of main concerns in foam displacement for enhanced oil recovery. This work presents the output of systematic laboratory screening of foamability and foam Stability of several surfactants. The surfactants examined were Brij 700, Triton X-100, Triton X-405, Zonyl FSO, Hitenol H-10, Hitenol H-20, Noigen N-10 and Noigen N-20. Foam was generated by sparging Carbon Dioxide gas at a fixed flow rate through surfactants solutions and R5 parameter as suggested by Lunkenheimera and Malysa (2003) were used for foam stability testing. The results indicate the foamability of all surfactants except for Triton X-405. Zonyl FSO and Hitenol H-10 were superior in term of foam stability with more stability as surfactants concentration increases. Equivalent optimum foam volumes were obtained for both surfactants but at higher concentrations of Hitenol H-10.

Foam stability and oil displacement efficiency were tested with different concentrations of Zonyl FSO and Hitenol H-10 solutions. The presence of oil at the volume fraction implemented, affect the stability of the foam columns. The effect depends on the surfactant-type and surfactants concentrations where stability decreases at low Zonyl FSO concentration range and at all concentrations range tested of Hitenol H-10. In case of Zonyl FSO observations indicate that oil stayed in the lamellas skeleton and plateau boarders with no drain out. To the contrary, Hitenol H-10 was able to lift good portion of the oil column but oil was drained out of the foam structure within a short period of time.

Flooding tests on Berea cores proved the ability of Zonyl FSO and Hitenol H-10 in controlling gas mobility and improving the displacement efficiency. Hitenol H-10 was more efficient as indicated by the incremental oil recovery obtained and the higher pressure drop encountered. Hitenol H-10 Foam injection on tertiary gas flooded reservoirs improves residual oil recovery indicating the potential of the process even at late stages of gas injection.
State-of-the-Art of In-Depth Fluid Diversion Technology: Enhancing Reservoir Oil Recovery by Gel Treatments
Authors: Han Ming , Alshehri Amar J. , Krinis Dimitrios , Lyngra Stig
Published: June 2014

In contrast to near-wellbore conformance control applications, polymer gels are applied in injector wells for reservoir scale applications for in-depth fluid diversion (IFD). Novel gel systems include weak gels, sequential injection for in-situ gels, colloidal dispersion gels, preformed gels, and microgels. The objective of an IFD process is to modify the prevailing reservoir inflow profile by gel treating the reservoir to significantly reduce effective permeability of high permeability zones that would otherwise dominate the water uptake. The weak gels or gel particles are treated as a flowing fluid and are custom-made for reservoirs with fractures or high permeability zones. The very weak gels form near the wellbore region, but continue to propagate into the reservoir. The gels eventually stop propagating deeper into reservoir due to the variation in pressure gradients and pore structures. The subsequent injection of fluids, water or chemical solutions, will redirect predominate flow paths to unswept reservoir zones, which improves oil sweep efficiency by waterflood (or chemical flood); thus, leading to enhanced oil recovery. The technology presents distinctive advantages to high-salinity and high-temperature reservoirs as compared to polymer flooding due to stability of cross-linked gel structures.

This paper presents a state-of-the-art review of IFD technologies including weak gels, sequential injection for in-situ gels, colloidal dispersion gels (CDG), microgels, and preformed particle gels (PPG). Moreover, a solution to the challenges of IFD applications in high-salinity and high-temperature reservoirs is presented.
FAWAG Using CO2 Philic Surfactants for CO2 Mobility Control for Enhanced Oil Recovery Applications
Authors: Sagir Muhammad , Tan Isa M , Mushtaq Muhammad , Talebian Seyedeh Hosna
Published: June 2014

The application of CO2 injection for mobilization of trapped oil in porous media is the most frequently applied method for EOR projects. Despite of the fact that the CO2 injection can effectively mobilize the trapped oil, many problems such as viscous fingering, gravity override, high ratio of CO2 to oil produced and early breakthrough are required to be resolved. In this context, the injection of surfactant solution for the reduction of CO2 mobility is a promising method. However, until now surfactants usage for mobility control is facing many challenges such as, adsorption of surfactants on rock, requirement of copious amounts of water, and loss in the thief zones of reservoir. These challenges can effectively be reduced by employing CO2 soluble surfactants, which have exhibited more practical advantages over conventional surfactants. A study has been conducted to evaluate new CO2 soluble surfactants for the CO2 mobility control for EOR applications. The IFT between CO2 and synthesized surfactants solution was studied for the initial screening process and is reported. The coreflood experiments were conducted by using Berea core sample in order to measure the mobility reduction factor (MRF). The MRF value of 3.1 was obtained by the incorporation of 0.5 % of novel CO2 philic foaming agent. Moreover, it was observed that the IFT between CO2 and brine appreciably decreased by using the surfactant in 0.5 % concentration. Coreflood results showed that, as compared to conventional surfactants, newly developed CO2 philic surfactants significantly reduced the mobility of the injected CO2.
Innovative Hot Oiling Operation in a Low BHP Well Minimizing Formation Damage: A Case Study
Authors: Haindade Zishaan M. , Mamen A. M.
Published: June 2014

The most common oil field wellbore problem encountered is paraffin deposition in the production tubing. The crude oil production is impeded by accumulation of such waxy residues that tend to clog the tubing, perforations and pores of the reservoir rock through which the oil flows.

Hot oiling with the help of coiled tubing is usually the method applied for removing paraffin deposits, however there is a high possibility of significant amount of the fluid injected into the well being lost to the formation, and hence the potential to damage the formation with low bottom-hole pressure is high. One such case was encountered in a well operated by Oil India Limited and this paper provides details of innovative technique applied for successful execution of hot oiling operation in the low BHP well minimizing formation damage.

As the well had very low BHP, there was a need to use circulating fluid with density lower than that of the source oil utilized for conventional hot oiling operation. Hence, it was decided to carry out the job by using a mixture of hot oil and nitrogen gas so as to reduce the density of the circulating fluid, thereby avoiding loss of injected fluid to the formation.

This paper provides the case study of the successful operation carried out in the well along with the detail calculations of pumping rates and pressure of both hot oil and nitrogen gas to obtain the desired density of the circulating fluid.
Field Deployment of a Novel Inlet Device for Multiphase Separators - Steps from R&D to Industrial Application
Authors: Jutaily Sulaiman A , Charry Prada Iran D. , Haider Syed Z. , Oshinowo Lanre , Vilagines Regis D.
Published: June 2014

A patented separator inlet device (SID) technology developed at Saudi Aramco's Research and Development Center (R&DC) is underway for a field trail in a gas-oil separation plant (GOSP) high-pressure production trap (HPPT) in 2014. The function of the SID is to enhance phase separation by promoting droplet coalescence and gas separation for mixed fluids flowing into a horizontal gravity separator vessel.

The paper describes the steps taken to bring the new technology to field stage after a successful R&D phase, detailing the challenges associated with scaling up and field installation of the prototype. Close collaboration between the R&D team, Engineering Services and plant owners, under the supervision of strongly supportive management, was essential for rapid field deployment of prototype technology with unconfirmed impact on the production rate.

The procedure for selecting a candidate separator vessel for the field trial and process integration study will be discussed. The SID installation in the candidate HPPT required modification to the existing operating liquid levels, which triggered a process evaluation study in the initial phase of the project. Engineering calculations and a field test demonstrated the proposed interface level reduction did not affect quality of the water and the oil sampled at the separator outlet ports.

To reduce risk in the absence of detailed industry standards for engineering multiphase flow processes, a combination of numerical modeling, physical testing and process evaluation at the candidate plant was employed in the prototype design and engineering phase.

The fabrication and field installation of the prototype SID were outsourced to an engineering contractor. The vendor contract allowed close monitoring and oversight by a Saudi Aramco R&D team on all design, fabrication and installation tasks. Open communication with the contractor was very useful in the preparation of the industrial deployment of the technology.
Intelligent Field Infrastructure Embedded Cyber Security Protection
Authors: Al-Sharif Noor , Almadi Soloman
Published: June 2014

Cyber Security is an essential building block of the overall safety and integrity of Intelligent Field Infrastructure (IFI). This is driven by the rapid evolution from proprietary to open standard based solutions. Moreover, the IFI special purpose hardware and software is now increasingly moving to a common platform and from isolation to interconnection with the Enterprise networks and systems. This evolution has resulted in growing and previously unforeseen cyber security threats. Therefore, a closer look is required to ensure cyber security is embedded into existing systems and an integral part of workflows, policies, and skillsets of the workforce.

In this paper, the authors share critical review for the intelligent field cyber security risk, available solutions, and the systematic approach in weaving cyber protection into the end-to-end system. The outcomes result in actual enhancements by considering cyber security as integral part of the overall IFI. Best practices and guidelines improvements are also highlighted.
Design and Development of Non-aqueous Suspension for Suspending Variedsized Solid Particulates as a Conventional Diverter
Authors: Agashe Snehalata , Patil Prajakta , Raysoni Neelam , Pandya Nisha
Published: June 2014

Using solid particulate additives is becoming difficult because of strict health, safety, and environmental (HSE) concerns and green operation initiatives taken by operators. When solid particulates are used as additives for downhole treatments, they are generally batch-mixed into the gelled fluid as long as the viscosity of the fluid is sufficient to prevent settling of the particles. It is possible that solid particles could settle and block the blending equipment; hence, an additional blender is required at location to mix such solid additives so that the main or primary blender remains functional throughout the job for subsequent mixing of other treatment fluids. Using the additional blender requires additional logistics, man power, and associated costs to the operator. Therefore, it is usually recommended to use liquid additives in the field to help avoid problems associated with using solids and related additional equipment issues.

This paper describes the systematic approach used for the development of a non-aqueous suspension fluid for suspending varied-sized (8 to 40 mesh; ~2400 to ~400 μ particles of a particulate diverter with a specific gravity of 1.29 g/cm3. The developed suspension is stable at ambient temperatures for more than 30 days. It remains free flowing for more than 30 days, even at 40°F, and the solid particles do not settle, even at slightly higher temperatures, such as 100°F. The chemical score index (CSI) of the formulation is 120, which shows that the suspension is environmentally acceptable. Performance of the suspension was evaluated through core flow experiments with brown sandstone core samples, which indicated that the fluid containing the newly developed suspension of the diverter particles did not cause formation damage to the samples used.
Application of Best in Class Reservoir Management Practices in the Production Startup of a New Giant Field Development through Integration of Real Time Data: A Case Study
Authors: Al-Ghamdi Faisal A. , Al-Otaibi Majid H. , Abitrabi Ballan Abdel N
Published: June 2014

The development team successfully met the production startup milestone for a giant carbonate oil field. Central to the story of this significant accomplishment was the application of best-in-class reservoir management practices through integration of real-time data. In this field development, Saudi Aramco invested the necessary resources to bring Intelligent Field capabilities to its field operations. The challenge to fully utilize real-time data for prudent reservoir management practices prior to field startup and during the pre-water injection phase was met by the development team as described in this case study.

This paper describes the nature of the reservoir development and puts emphasis on the advantageous role that real-time data acquisition has played in allowing key reservoir management objectives to be met. The field is equipped with state-of-the-art data sensing and transmission capabilities. Examples of key reservoir management goals that will be discussed in this paper include maintaining reservoir pressure, water injection efficiency assessments, dynamic reservoir characterization process, real-time reservoir simulation model calibration process, and the concurrent release of field production/injection guidelines.
Isothermal Oil Compressibility Curve Crossing
Authors: Al-Marhoun Muhammad Ali
Published: June 2014

Oil compressibility above bubble point pressure is important in reservoir simulation, material balance calculations, design of high-pressure surface-equipment and the interpretation of well test analysis. Accurate calculation of oil compressibility is very important for reservoir evaluation.

The oil compressibility above bubble point pressure increases with increasing temperature and decreasing pressure, therefore, curves at the same pressure and different temperatures should not cross each other.

The conventional method of obtaining oil compressibility is from individual temperature measurement of pressure-volume data of constant composition expansion test. The oil compressibility determination involves pressure-volume function and its derivative at each temperature. This individual estimation with derivative calculation makes oil compressibility evaluation very sensitive to small derivative change that may lead to an invalid and non physical behavior of curve crossing.

This paper presents a special constrained multiple linear regression optimizations that ensures non-crossing of oil compressibility curves above bubble point pressure for multiple temperatures.
Comprehensive Reservoir Monitoring Program: Challenges, Design, Implementation, and Added Value in a Large Carbonate Reservoir
Authors: Al-Julaih Ali , Al-Dawood Naseem
Published: June 2014

Reservoir monitoring is an important aspect of prudent reservoir management to sustain productivity and achieve higher hydrocarbon recoveries. Monitoring is a process that comes in various forms, such as that of flood front advancement and reservoir saturation changes and quantification. Designing and implementing an effective monitoring program to track fluid advancement and quantify remaining oil saturation is a reservoir management best practice that ensures optimum sweep is achieved; and so is crucial for all fields, regardless of their state of maturity. The necessity for such programs becomes more critical as fields mature.

Reservoir saturation monitoring programs are usually faced with several challenges, including: mixed and low fluid salinity, tool limitations, borehole conditions and reservoir heterogeneity. Overcoming these challenges requires comprehensive programs that encompass adoption and integration of various derived saturation techniques.

This paper will discuss a reservoir monitoring program of a large carbonate field that has produced continuously for several decades. The monitoring program includes "key monitoring wells" in addition to drilling new evaluation wells that are strategically selected and are mostly located in well flooded areas. Time-lapse production and fit for purpose saturation logs are run in the existing wells, while extensive in situ measurements of fluid saturation are collected in the case of the new wells, to monitor saturation changes and track the movement of fluids.

The paper will also discuss the various methodologies adopted to address the aforementioned challenges. It will illustrate how the monitoring program has aided in tracking fluid movement, quantitatively determining fluid saturations and assessing sweep efficiency (Ed, Ev and Ea). In addition, the paper will show how the collected information was a catalyst in identifying sweet spots in flooded regions, and therefore guiding development activities for maximizing hydrocarbon recovery, especially from mature areas.
Optimizing Acid Stimulation Treatment Design in South Ghawar Power Water Injectors Wells
Authors: Tammar Hasan , Alkadem Mortada , Jandal Ahmed , Atayev Nurymyrat
Published: June 2014

Acid proved an efficient near wellbore skin damage removing agent in carbonate production and injection wells. Nevertheless, improving acid stimulation design is a continuous need in oil industry. Formation analysis logs for some of South Ghawar power water injectors have shown a significant amount of residual oil dominating the open hole interval. This phenomenon results in wells transmissibility reduction, which reflects negatively on injection rate.

A unique type of de-paraffin organic solvent was recently introduced to acid treatment design in South Ghawar PWIs to tackle injection impediment caused by high irreducible oil saturation. This solvent demonstrated a great capability in removing and flushing off residual oil, wax and asphaltene deposits in the reservoir matrix. Adding this solvent to pre-flush the rock enhanced the main acid treatment propagation into the reservoir, as well as water injection afterwards.

This paper presents the influence of the organic solvent on some of South Ghawar horizontal and vertical PWIs performance after acid treatment. It will also compare the injectivity of wells — with similar parameters and properties — that were acidized without adding this organic solvent in treatment. Differences in results due to modification of this product will also be discussed.
Advanced Well Completion Designs to Meet Unique Reservoir and Production Requirements
Authors: Jacob Suresh , Naimi Khalid M.
Published: June 2014

Well Completions design is continuously evolving to meet increasing requirements of down hole monitoring and control. The design of well completion has become more sophisticated as these requirements increase. Nowadays in the industry, it is rare to find a well completion that does not have some type of down hole sensor or inflow control. This paper presents overview of six different well completions designed to meet different reservoir and production requirements. Each of these design are integrations of existing and new technologies. The technologies presented in the paper range from inflow control devices and open hole packers placed in the reservoir section, multilateral junction systems, through permanent down hole sensors, surface controlled down hole valves and electric submersible pumps in the production tubing. The paper also discusses briefly the integration of the down hole equipment with surface control panels and SCADA communication systems. Different well types like oil producers, water injectors and artificial lift wells are discussed.