Total (Qatar)

The purpose of this study was to investigate the clinical effect of a supplementary diet containing heat-killed lactic acid bacterium Lactobacillus paracasei K71 (LAB diet) on adult patients with atopic dermatitis (AD). A randomized, double-blind, placebo-controlled study was conducted in 34 adult type AD subjects who were treated with conventional topical corticosteroid and tacrolimus. LAB diet or placebo was added over 12 weeks. The primary end-point was the clinical severity of AD which was evaluated by a severity scoring system proposed by the guideline of the Japanese Dermatological Association. The effect was also secondarily evaluated by itch scores of visual analog scales (VAS), quality-of-life (QOL) impairment scores of Skindex 16 and consumption amounts of topical therapeutics. Data on these four assessment variables were collected at baseline and at week 4, 8 and 12. Within the study population, the skin severity scores were significantly decreased from baseline at week 8 (P<0.05) and at week 12 (P<0.01) in the LAB diet group but not in the placebo group. Influence of LAB diet on itch scores or QOL impairment scores was not evident. The consumption of topical therapeutics in the placebo group was 1.9-times greater in total amount compared with the corresponding value in the LAB diet group during the intervention period, although there was no significant difference. No LAB diet- or placebo-related adverse events were observed. We concluded that the LAB diet may have some benefits as a complementary therapy for adult AD patients who are managed with the conventional treatment.

Abstract How do we learn to be religious? To make sense of this process should we emphasize the habitual reinforcement of bodily rituals? Or the active role of individuals in making decisions about faith at key moments? Or should we turn to cognitive science to explain the universal structures on which religiosity is built? And how does a relatively devout minority pass on religion in a generally secular Western context? What significance does religion have for family life in this situation? And how does a religious identity interact with other kinds of collective identification, for example with a nation, ethnic group, or a locality? These are some of the questions that Muslim Childhood deals with. This book is about ordinary British Muslims’ everyday religious socialization of children in early and middle childhood. It provides a detailed description of how Muslim families in a secular Western context attempt to pass on their faith to the next generation. It is rooted in detailed qualitative research with 60 Muslim families in one British city. The authors’ own analysis of survey data suggests that Muslims in the UK pass on their faith to the next generation more effectively than other religious groups. This book is in part an attempt to explain why that might be.

Dry reforming of methane (DRM) is an important technology that utilizes CO2 to convert methane to a mixture of H2 and CO (syngas). Commercial applicability of DRM has been challenged by the high energy requirement, susceptibility to coke formation, and low-quality syngas (syngas ratio, H2/CO ∼ 1). On the other hand, DRM provides an attractive pathway to the cost-effective sequestration of CO2 via transformation to value-added chemicals and fuels. DRM may be used in conjunction with other reforming technologies to produce the needed quality of syngas and to exploit synergism in energy release and demand. In this work, an optimization-based approach is used to compare the carbon footprint of conventional reforming technologies with other processes involving DRM to produce syngas of different H2/CO ratios. Technical, economic, and environmental metrics are used to assess the various options. Additionally, the model accounts for the carbon footprint associated with the reforming process, catalyst regeneration, and other energy requirements. The results of the optimization formulation show that the CO2 fixation using DRM is highly dependent on the desired syngas ratio. Net CO2 fixation occurs only at low syngas ratios of 1 and below. The results also indicate that producing syngas through a parallel reforming network involving existing technologies (steam methane reforming and partial oxidation) with DRM does not result in overall CO2 emissions reduction. Finally, two novel process concepts have been studied—CO removal from DRM syngas (DRM + COSORB) and H2 addition from an external source. Both these cases, while producing high H2/CO ratio syngas, have potential in terms of CO2 emissions reduction and competitive operating costs but will have certain limitations. The DRM + COSORB (captured CO sold as feedstock) process was found to be the best among all options studied in terms of overall reduction of CO2 emissions and operating costs.

1,2-Propylene glycol and glycerin, principal components of e-liquids, can thermally degrade to form acetaldehyde, acrolein, and formaldehyde when heated in electronic nicotine delivery systems (ENDS). Recently the flavors in e-liquids were suggested to be the major source of these aldehydes. We used the same 10 ENDS devices to test 5 e-liquid formulations (four flavored & one corresponding non-flavored) and measured device mass loss and levels of acetaldehyde, acrolein, and formaldehyde (30 replicate measurements per formulation). Despite finding reasonable variability in measurements of device mass loss, two out of 10 ENDS devices tested produced outlier values for aerosol levels acetaldehyde, acrolein, and formaldehyde. After removing these devices from further analysis, acceptable variability (≤20% RSD) in aerosol levels of acetaldehyde, and formaldehyde were found. The flavored formulations tested resulted in a consistent and selective increase of 150%-200% in acetaldehyde, no increase or decrease in acrolein and depending on the flavor formulation, an increase, a decrease or no change in formaldehyde levels. Comparison of our results to the literature illustrates the need for development of a standardized ENDS testing protocol. Our results further support that device variability must be fully characterized and considered before assessing the impact of e-liquid formulations.

OBJECTIVE: To examine the prevalence of burnout and its work-related factors among public health providers (PHP) during the COVID-19 pandemic. METHODS: We surveyed 366 PHP in May 2021 on their burnout, demographic, and work-related characteristics. Logistic regression analyses were conducted to identify associated factors. RESULTS: 45% PHP reported burnout. Higher PHP burnout was associated with younger age (AOR 0.96, 95% CI 0.93-0.99), prolonged COVID-19 involvement (AOR 2.35, 95% CI 1.16-4.72), as well as perceiving medium (AOR 2.10, 95% CI 1.27-3.48) and high emotional demand (AOR 4.45, 95% CI 1.67-11.77), low (AOR 2.10, 95% CI 1.27-3.48) and medium (AOR 4.18, 95% CI 1.64-10.59) role clarity, medium job satisfaction (AOR 3.21, 95% CI: 1.11-9.29), and low organisational justice (AOR 3.32, 95% CI 1.51-7.27). CONCLUSIONS: Improving job content and organisational characteristics may be key to reducing PHP burnout.

Abstract In this paper, results are presented from a series of scale inhibitor core flood experiments using oil reconditioned reservoir cores from four North Sea fields. Phosphonate, poly phosphino carboxylic acid, poly acrylic acid and sulphonated acrylic acid scale inhibitors were used in order to evaluate their performance prior to field squeeze application. Different methods of application were considered including both (i) adsorption/desorption and (ii) precipitation/ redissolution type squeeze treatments. The return profiles for the different types of applications and the different chemistries are compared as are the observed formation damage effects. The advantages and disadvantages are outline for these two mechanism in terms of the extending squeeze lifetime vs potential for formation damage. It is intend that this paper contributes to the development of better designed and safer field applications of both adsorption and precipitation scale inhibitor squeeze treatments in the light of individual reservoir petrography and petrophysical properties.

Abstract It is well known that the use of hydrochloric acid to clean up and restore permeability of open holes drilled in limestone formations is a questionable procedure. It is necessary to remove, not only the filter cake at the well bore face but, more importantly, the low permeability crushed zone created during the drilling operation. To achieve uniform treatment of the entire openhole section with hydrochloric acid is difficult: the rapid reaction of the acid in downhole conditions often creates a localized loss zone, through which most of the treating fluid is lost so that treatment of the entire section is inefficient. Traditional completion practice on Al Khalij field (Qatar) involved cemented casing, perforations and subsequent stimulation of the limestone with retarded emulsified hydrochloric acid and ball sealers. This paper describes a new and different approach, which involves leaving drains in openhole condition and using a slow acting stimulation treatment for damage removal and stimulation. The stimulation treatment comprises a starch enzyme to degrade the most troublesome polymer and an organic compound that reacts with the carrier brine to release organic acid in situ over a period of several hours. The breaker fluid is introduced to the openhole section in a neutral pH condition, thus enabling it to be distributed over the entire interval of interest. Enough acid is generated over the subsequent 12 hours to remove the filter cake and clean up the crushed zone. This system has recently been used on several occasions on this field, with openhole drain length ranging from 530 to 1890 m (1,740 to 6,200 ft) and treatment volumes ranging from 20 to 115 m3 (125 to 725 bbl). Losses from these wells occurred after the predicted elapsed time. Details are provided of how the jobs were carried out and the results achieved.

OBJECTIVE: To evaluate the variation in mobility during hospitalization in an intensive care unit and its association with hospital mortality. METHODS: This prospective study was conducted in an intensive care unit. The inclusion criteria included patients admitted with an independence score of ≥ 4 for both bed-chair transfer and locomotion, with the score based on the Functional Independence Measure. Patients with cardiac arrest and/or those who died during hospitalization were excluded. To measure the loss of mobility, the value obtained at discharge was calculated and subtracted from the value obtained on admission, which was then divided by the admission score and recorded as a percentage. RESULTS: The comparison of these two variables indicated that the loss of mobility during hospitalization was 14.3% (p < 0.001). Loss of mobility was greater in patients hospitalized for more than 48 hours in the intensive care unit (p < 0.02) and in patients who used vasopressor drugs (p = 0.041). However, the comparison between subjects aged 60 years or older and those younger than 60 years indicated no significant differences in the loss of mobility (p = 0.332), reason for hospitalization (p = 0.265), SAPS 3 score (p = 0.224), use of mechanical ventilation (p = 0.117), or hospital mortality (p = 0.063). CONCLUSION: There was loss of mobility during hospitalization in the intensive care unit. This loss was greater in patients who were hospitalized for more than 48 hours and in those who used vasopressors; however, the causal and prognostic factors associated with this decline need to be elucidated.

The introduction of total purchasing pilots (TPPs) into the National Health Service (NHS) gave general practitioners (GPs) significant new opportunities to take responsibility for the development of community and continuing care (CCC) services. Based on five case studies of TPPs involved in developing CCC this paper asks three questions: (1) to what extent were the TPP's involvement in CCC informed by an awareness of CCC policy?; (2) were TPPs involved in joint commissioning to develop integrated purchasing or provision which was informed by population based needs assessment?; (3) were TPPs seeking to involve users, carers and voluntary agencies in their plans? The findings indicate that TPPs showed little awareness of national or local policy for CCC, although their project initiatives did address some of the policy issues (in particular a recognition of the need for joint working at the practice level). At the time of fieldwork, four of the case study TPPs had begun to investigate the potential for integrated purchasing, and three of them had relatively sophisticated models of both horizontally and vertically integrated provision of care. However, the TPPs developments were not based on systematic population based needs assessment. The paper concludes that there is potential for the primary care led groups proposed in the recent white papers in England, Scotland and Wales to improve integration of care both horizontally and vertically. However, they may need policy guidance and push to: encourage them to put CCC high on their agenda for action; to work with people with expertise in population based, prevention focused, needs assessment; and to find innovative ways to include users, carers and voluntary agencies. Incentives or levers (such as control over budgets) may be needed to promote joint working between staff in different agencies.

The present study is focused on the experimental evaluation of the non-intrusive electric resistance tomographic (ERT) technique in the presence of different types of water-based drilling fluids, i.e., Newtonian (water) and non-Newtonian (0.05 wt% and 0.1 wt% polymers). The experiments were conducted in a 6.16-m long horizontal flow loop with an inner and outer diameter of 2.5 and 4.5 inches. The tests covered a variety of hydrodynamic and operational parameters, such as the density (997–1001 kg/m3) and apparent viscosity (0.889–2.54 cP) of the fluids as well as different eccentric conditions (0–0.6), mass flow rates (170–365 kg/min), and drill pipe rotations (0–120 RPM) with horizontal drilling conditions. In this investigation, we analyzed the ERT-obtained average volume fraction (AVF), maximum volume fraction (MVF), and cuttings residence time. The results highlighted that the ERT technique is useful in situ tool for detecting solid particles in various cuttings transport scenarios (different drilling fluids, mass flow rates, and eccentricities). The findings also revealed that an increase in the liquid flow rate influenced cuttings transport. Non-Newtonian fluids performed relatively better than Newtonian (water) fluid at higher flow rates (for equivalent pump output and equivalent Reynold number conditions) as it provides higher AVF and MVF quantities due to their rheological properties hold cuttings in a suspended form. Inner pipe rotations also significantly enhanced the cuttings transport by adding induced helical motion and vorticities in the annulus. On the other hand, eccentricity in the annulus caused hindrance in the cuttings transport movement due to reduced active solid transportation or effective area, resulting in a more extended horizontal bed formation.

Summary Hole cleaning is a concern in directional and horizontal well drilling operations where drill cuttings tend to settle in the lower annulus section. Laboratory-scale experiments were performed with different non-Newtonian fluids in a 6.16-m-long, 114.3- × 63.5-mm transparent annulus test section to investigate cuttings transport behavior. This experimental study focused on understanding the cuttings transport mechanism in the annulus section with high-speed imaging technology. The movement of cuttings in the inclined annular section was captured with a high-speed camera at 2,000 frames/sec. Also, cuttings bed movement patterns at different fluid velocities and inner pipe rotations were captured with a digital single-lens reflex video camera. The electrical resistance tomography (ERT) system was used to quantify the cuttings volume fraction in the annulus. Different solid bed heights and cuttings movements were observed based on fluid rheology, fluid velocity, and inner pipe rotation. The mechanistic three-layer cuttings transport model was visualized with the experimental procedure. This study showed that solid bed height is significantly reduced with an increase in the inner pipe rotation. This study also identified that cuttings bed thickness largely depends on fluid rheology and wellbore inclination. The image from the high-speed camera identified a downward trend of some rolling particles in the annulus caused by gravitational force at a low mud velocity. Visual observation from a high-speed camera identified a helical motion of solid particles when the drillpipe is in contact with solid particles and rotating at a higher rev/min. Different cuttings movement patterns such as: rolling, sliding, suspension, helical movement, and downward movement were identified from the visualization of a high-speed camera.

Abstract To face the new challenges of production metering and back allocation, TOTAL is making an important effort to develop and test new approaches to improve its current production metering systems particularly for multiphase conditions. New technologies are tested through pilot applications within different subsidiaries worldwide. Thanks to these pilots, the suitability of various approaches to the needs of each asset can be analyzed and tested in detail. The SPE-149908 (M. Haouche 2012) paper presented a Virtual Flow Meter (VFM) field pilot in Qatar. The approach used on this VFM is the Data Validation and Reconciliation (DVR). The single Well model of the VFM is an assembly of three main units: Reservoir unit, Electrical Submersible Pump (ESP) unit and Production Tubing unit. The conclusion was that the VFM was catching-up the production trends of all the Wells of the pilot. However, the VFM results are not quantitatively comparable to the production measurements, especially when the VFM is running far away from the calibration period. A recommendation was to enhance the ESP model that controls mainly the information on the flow rate. The present paper describes a new method for modeling the ESP performances in the VFM. This method takes into account the impact of the Gas on the ESP performances. Results are presented for three operational cases to see the benefits of this method and where it is applicable. The ESP operational data have been considered for a long time period in order to get a representative range of operational conditions. Conclusions are made on the capabilities of the new method to assess the impact of Gas on the ESP operational performances.

Stochastic (or geostatistical) impedance inversion techniques have great potential in addressing key questions in reservoir characterization. They work at the vertical scale of reservoir models and, therefore, at higher resolution than the seismic data. They produce multiple equiprobable results which provide an assessment of, the uncertainties, and they are ideally suited for integrating non-seismic information in the inversion process. However, two issues have slowed the acceptance of stochastic impedance inversion techniques. First, there is suspicion of‘ unconstrained random noise generators’, which appear to offer extra information for free, and, secondly, managing and extracting value from multiple realizations is difficult. For these reasons, faster deterministic inversion approaches, resulting in a single lower-resolution impedance volume, with less quantified uncertainty, are more commonly used when building reservoir models. To address the first issue, we have developed ways of integrating 3D constraints from sedimentary modelling with the geostatistical impedance inversion method, since these two approaches bring complementary information on reservoir properties. The resulting high-resolution multiple realizations of impedance are combined with uncertainties from petrophysical regression analysis to produce multiple realizations of reservoir properties (e.g. porosity), and from each an estimate of total pore volume. We illustrate the benefits of this multiple realization work flow applied to data from a shallow marine siliciclastic reservoir. A comparison of the seismic/sedimentologically constrained reservoir models with those constrained by well data only has demonstrated more accuracy and better control on the spatial variability of reservoir properties. In this example, however, adding more constraints results in a broader range of possible reservoir models and a more meaningful uncertainty assessment. We conclude that our models constrained by well data only were derived with unrealistic simulation parameters and an over-optimistic assessment of a priori uncertainty.

OBJECTIVE: An 8.0-magnitude earthquake struck Sichuan province of China on May 12, 2008. Over the next 10 days, the firstly arrived uniformed pediatricians in the epicenter zone took part in emergency relief care for children. The investigations of major injuries and diseases in children were taken. METHODS: Demographic data collected included (if possible) age, date of presentation, injury, disease, and surgery performed. RESULTS: Total casualties were estimated to be more than 80,000, and much more were injured. Eight hundred eighty-two inpatients were treated by the relief team during the first 10 days. Of 882 inpatients, 192 (21.8%) were younger than 18 years. Children's ages were not evenly distributed. Twenty-seven patients were neonates, infants, and toddlers (14%), 105 were school-aged (55%), and were 60 adolescents (31%). The admitted children had 256 injuries. Limb (106 cases, 55.2%) and body surface (67 cases, 34.9%) were the majorly injured locations. One hundred twenty-seven cases (66.2%) had simple open injuries, and 106 (55.2% had fractures. The children's conditions were evaluated as mild (121 cases, 63.0%), moderate (56 cases, 29.7%), severe (8 cases, 4.2%), and fatal (7 cases, 3.7%). CONCLUSIONS: More than 20% of patients requiring hospitalization were children. School-aged children were heavily injured. The increase in infectious diseases followed on. The data show that there is an immediate need for orthopedic and general surgery skills, and pediatricians should play an important role in early rescue and subsequent control of infectious diseases in a huge earthquake hazard.

Although serum bile acids and total cholesterol (TC) are closely related to liver cirrhosis, the potential diagnostic value of total bile acid-to-cholesterol ratio (TBA/TC) for liver fibrosis is unclear. The present study aimed to evaluate the value of TBA/TC in the diagnosis of cirrhosis and the relationship between TBA/TC and significant liver fibrosis in chronic hepatitis B virus (HBV) infected patients without cholestasis.667 patients with alkaline phosphatase (ALP) ≤ 1.5 upper limit of normal (ULN) and gamma-glutamyl transferase (GGT) ≤ 3 ULN were rigorously included in this cross-sectional study. Liver biopsy was performed in 32 patients and METAVIR scoring system was used to evaluate liver fibrosis stage. Liver ultrasound elastography was performed in 138 patients, significant fibrosis was defined as fibrosis ≥ F2. Multiple logistic regression as well as receiver operating characteristic (ROC) curves analyses were performed.Compared to patients with non-cirrhosis, TBA and TBA/TC were significantly higher in cirrhosis while TC was significantly lower (all P < .001). In multivariate analysis, TBA/TC was also independently associated with cirrhosis [odds ratio (OR) = 1.102, 95% confidence interval (CI): 1.085-1.166]. The area under the curve (AUC) of TBA/TC (0.87) was almost equivalent to the aspartate aminotransferase to platelet ratio index (APRI, AUC = 0.84) and fibrosis 4 score (FIB-4, AUC = 0.80), and the optimal cut-off value for TBA/TC to diagnose cirrhosis was 2.70. Among the patients performed liver biopsy, TBA/TC were significantly higher both in significant fibrosis and cirrhosis as well as significantly correlated with fibrosis stage (all P < .001). Furthermore, In patients performed liver ultrasound elastography, TBA/TC was also independently associated with significant fibrosis (OR = 1.040, 95% CI: 1.001-1.078).Assessment of TBA/TC could serve as an additional marker of significant liver fibrosis and cirrhosis in non-cholestatic chronic HBV infection.

Abstract An accurate description of reactive transport phenomenon in porous media has major applications for many processes such as, contamination in groundwater resources, carbon capture and storage, enhanced oil recovery, and acid stimulation. These processes, involve surface reaction coupled with flow that result in dynamic alteration of the porous media structure. More particularly, in well acidizing, an accurate understanding and control of the stimulation operations outcomes still represents a major challenge in heterogeneous carbonates. The objective of this paper is to describe how an integrated experimental and numerical approach is adopted to develop a core-scale reactive transport simulator that could be used to investigate acidizing efficiency in carbonates. A series of core flooding experiments were performed on Richemont carbonate blocks from queries at reservoir temperature. A back pressure valve system is used to eliminate the effect of free gaseous CO2 on the flow dynamics of acid. Moreover, mathematically, a continuum-scale model was used to describe the reactive transport phenomenon. This model consists of fluid transport, continuity, species balance, and porosity evolution equations at a continuum scale. The porous media characteristics such as permeability and pore radius are obtained as a function of local porosity using closure relations. The rock properties required as input to the model come from numerous experimental techniques such as computed tomography (CT), Mercury injection capillary pressure (MICP), and X-ray diffraction (XRD) The numerical results obtained using the model, show a close match with the experimental observations, in terms of pore volume to breakthrough (PVBT). Additionally, the developed model was able to reproduce the different dissolution regimes along with the transient pressure response, as observed experimentally.

Summary Well abandonment is one of the biggest challenges in the oil and gas industry, both in terms of cost and effort as well as the technical hurdles associated with wellbore sealing for an indefinite term. A mechanism that may be exploited to simplify well abandonments is using natural shale or salt formations for the creation of annular barriers. Currently, uncemented annuli often require casing cutting and pulling or milling before abandonment plugs can be set, which necessitates the use of a drilling rig. This is an expensive, time- and labor-intensive process, particularly offshore. However, shale or salt creep may naturally form a barrier behind uncemented casing sections. With a qualified annular shale barrier in place, the well may only require the setting of abandonment plugs within the existing casing string(s), a task that can often be done rigless and with significantly less effort. The work described in this paper presents the results of a rock mechanical investigation into the creep behavior of North Sea shales and their ability to form effective annular barriers. Field core from the Lark shale, a member of the Hordaland Group, was used to conduct dedicated, customized experiments that simulated the behavior of shale confined under downhole effective stress, pressure, and temperature conditions to fill in an annular space behind a simulated casing string. Full-scale triaxial rock mechanics equipment was used for testing cylindrical shale samples obtained from a well-preserved field core in a setup that mimicked an uncemented casing section of a well. The deformation behavior of the shale was monitored for days to weeks, and the formation of the annular barrier was characterized using dedicated strain measurements and pressure pulse decay probing of the annular space. The large-scale laboratory results clearly show that the Lark shale will form competent low permeability annular barriers when left uncemented, as confirmed using pressure-pulse decay measurements. They also show that experimental conditions influence the rate of barrier formation; higher effective stress, higher temperature, and beneficial manipulation of the annular fluid chemistry all have a significant effect. This then opens up the possibility of activating shale formations that do not naturally create barriers by themselves into forming them (e.g., by exposing them to low annular pressure, elevated temperature, different annular fluid chemistry, or a combination of these). The results are in very good agreement with field observations reported earlier by several North Sea operators.

Blood doping in sports is prohibited by the World Anti-Doping Agency (WADA). To find a possible biomarker for the detection of blood doping, we investigated the changes in blood stored in CPDA-1 blood bags of eight healthy subjects who donated one unit of blood. Aliquots were taken on days 0, 14, and 35. Platelet-free plasma was prepared and stored at -80°C until analysis on a flow cytometer dedicated for the analysis of microparticles (MPs). Changes in the number of red blood cell (RBC) -MPs were highly significant (p < 0.0001) with a mean of 219 (10^3/μL) on day 0 changing to 23 120 (10^3/μL) on day 14 and 29 310 (10^3/μL) on day 35. We conclude that RBC-MPs seem to be a promising biomarker for doping control but confirmation by a transfusion study is necessary.

Abstract The Al Khalij field, located offshore Qatar, was discovered in 1991 and put into production in 1997. The field is original in many aspects. It is one of the few carbonate reservoirs with a stratigraphic closure, the oil being trapped in the upper part of a monocline due to a lateral variation in reservoir facies. In addition, the reservoir lies within the capillary transition zone and consists of a succession of highly conductive oil bearing layers ("drains") in between matrix layers of poor permeability. Due to the complex reservoir architecture and the large uncertainties in the reservoir dynamic behavior, the field has been developed in several stages to improve understanding and minimize risks. This paper will discuss on the development of Al Khalij field and will illustrate how advanced technological solutions were applied to overcome complex geological and reservoir problems in order to enhance reservoir performance and well productivity. More specifically the paper will illustrate how: ➢High-resolution 3D seismic has revealed additional areas for development, which were previously considered to be uneconomic.➢Innovative well design in a stair-step manner was implemented to intersect productive layers and increase drainage efficiency with a limited number of wells.➢Stimulation and completion techniques were adapted to optimize productivity while limiting water production.➢Water injection was implemented in the field after validation of its effectiveness through pilot water injection, including tracer test, and through reservoir simulation studies.

Abstract The southern coast of the Arabian Gulf is considered a good example of an arid carbonate depositional system. The objective of this field investigation is to better elucidate the dynamic controls on the character and pattern of the depositional belts in a carbonate-evaporite lagoonal setting. The interpretation of this lagoon is based on combined field examination and laboratory analyses of surface samples, and this has resulted in an updated depositional model for carbonate-evaporite lagoonal settings. This study highlights the effects of sediment transport by longshore currents, with the formation of sand spits that gradually closed the lagoon during their southwards migration. The associated narrow and elongated back-barrier settings consist of tidal-dominated muddy sediments affected by a network of tidal channels. This wave-dominated high-energy system has generated several carbonate barrier and back-barrier units that migrated southwards and seawards during the last few thousands of years. This updated depositional model significantly differs from shoreline-parallel facies tracts of the classical Trucial Coast model, where the dominant wind is orientated perpendicular to the coastline. Conversely to the sediment belts of the Trucial Coast, the Al Dakhirah lagoon displays a strongly asymmetrical pattern of the sediment belts, marked by a southwards and seawards migration.