scholarly journals Degradation of Reservoir Quality by Clay Content, Unayzah Formation, Central Saudi Arabia

GeoArabia ◽  
1997 ◽  
Vol 2 (1) ◽  
pp. 49-64
Author(s):  
George R. Polkowski
Keyword(s):  
Saudi Arabia ◽  
Clay Minerals ◽  
Clay Content ◽  
High Water ◽  
Weight Percent ◽  
Control Measures ◽  
Reservoir Rock ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Iron Hydroxides

ABSTRACT Reservoirs in Central Saudi Arabia are important new sources of light sulfur-free crude oil. Development work on these wells has shown the adverse effect of authigenic clay minerals on their productivity or injectivity. The clay minerals may be affected during drilling of the well, during completion, during production, and/or injection. Kaolinite, chlorite, illite, and ordered and random mixed layer illite/smectite are commonly occurring authigenic clay minerals within the Permian Unayzah reservoir rock. As little as 2 weight percent clay causes permeability to be drastically reduced. Formation damage due to clay minerals results from: (1) swelling of smectite caused by injection water or drilling fluids of low salinity; (2) clay mineral migration and subsequent pore blockage; (3) precipitation of gelatinous pore-blocking iron hydroxides caused by the dissolution of chlorite by acid; (4) high water saturations; and (5) disaggregation of poorly consolidated parts of the reservoir into its component sand grains if the weak clay cements are disturbed. The implementation of clay control measures has resulted in increased production while minimizing formation damage.

Current Status of Knowledge and Awareness of Diabetes Mellitus in Saudi Arabia

2020 ◽  
Vol 16 ◽  
Author(s):  
Asirvatham Alwin Robert ◽  
Ahmad Dakeel Al Awad ◽  
Mohamed Abdulaziz Al Dawish
Keyword(s):  
Diabetes Mellitus ◽  
Saudi Arabia ◽  
Disease Risk ◽  
Current Knowledge ◽  
Adult Population ◽  
Management Training ◽  
Control Measures ◽  
Current Status ◽  
Treatment Modalities ◽  
The Government

Abstract: Diabetes mellitus (DM) is a chronic disease, and the complications may be life-threatening; however, with proper treatment and control measures, it can be very well-managed. Self-management training and education of diabetes are critical in diabetes care and management. It is essential that patients with diabetes must have a comprehensive understanding of the nature of the disease, risk factors, complications, and possible treatment modalities to attenuate the complications. Over the last few years, DM in Saudi Arabia has been rapidly growing at an alarming rate. It has affected around one-fifth of the adult population, and by 2030, the numbers are predicted to rise further and exceed more than double the present number. An estimated tenfold increase has been reported over the past three decades in Saudi Arabia. However, there has not been much research focusing on understanding the knowledge and awareness of DM in Saudi Arabia as compared to developed nations. This review aims to present an overview of the current knowledge and awareness level of DM among the population of Saudi Arabia through an extensive review of the currently available literature. The review findings could be of immense assistance to the government, healthcare systems, educational institutions, and researchers to develop evidence-based programs, policies, and guidelines towards increasing the knowledge and awareness about diabetes and its management, so that early detection and management can be ensured to control the escalating burden of diabetes, in Saudi Arabia.

Methicillin-Resistant Staphylococcus aureus in Two Tertiary-Care Centers in Jeddah, Saudi Arabia

2001 ◽  
Vol 22 (4) ◽  
pp. 211-216 ◽  
Author(s):  
Tariq A. Madani ◽  
Nabeela A. Al-Abdullah ◽  
Ali A. Al-Sanousi ◽  
Tawfik M. Ghabrah ◽  
Shadia Z. Afandi ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Saudi Arabia ◽  
Tertiary Care ◽  
Age Groups ◽  
Clinical Manifestations ◽  
Total Mortality ◽  
Control Measures ◽  
Methicillin Resistant ◽  
Mrsa Infection ◽  
Tertiary Care Hospitals

AbstractObjective:To review clinical experience with methicillin-resistant Staphylococcus aureus (MRSA) in tertiary-care hospitals in Jeddah, Saudi Arabia.Design:Retrospective review for the year 1998.Setting:Two tertiary-care hospitals.Methods:Results of MRSA-positive cultures of clinical specimens obtained as part of investigations for suspected infections were retrieved from the microbiology laboratories' records. Charts of patients were reviewed, with standardized data collection.Results:Of 673 S aureus isolates identified, 222 (33%, or 6.8 isolates/1,000 admissions) were MRSA Overall MRSA prevalence was 2% in 1988. Nosocomial acquisition occurred in 84.2% of cases. All age groups were affected, and 52% of patients had at least one comorbidity. MRSA prevalence was highest in the intensive care units (26.6% of all isolates), the medical wards (24.8%), and the surgical wards (19.8%). Seventy-three percent of isolates caused infection; the rest represented colonization. Surgical wounds (35.2%), the chest (29%), and central venous catheters (13%) were the most common sites of infection. Bacteremia occurred in 15.4% of patients. Local signs (84%) and fever (75.9%) were the most common clinical manifestations. Respiratory distress and septic shock occurred in 30.2% and 13.6% of cases, respectively. Of 162 patients with MRSA infection and 60 patients with MRSA colonization, 95.7% and 70% received antibiotics in the preceding 6 weeks, respectively (P<.0001). The total mortality of patients with MRSA infection was 53.7%: 36.4% as a result of MRSA infection and 17.3% as a result of other causes.Conclusions:The prevalence of MRSA is high and rapidly increasing in the two hospitals, as it is worldwide. Control measures to prevent die spread of MRSA in hospitals should continue, with reinforcement of hygienic precautions and development of policies to restrict the use of antibiotics.

scholarly journals Examining and investigating the impact of demographic characteristics and chronic diseases on mortality of COVID-19: Retrospective study

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257131
Author(s):  
Abbas Al Mutair ◽  
Alya Al Mutairi ◽  
Saad Alhumaid ◽  
Syed Maaz Abdullah ◽  
Abdul Rehman Zia Zaidi ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Saudi Arabia ◽  
Binary Logistic Regression ◽  
Demographic Characteristics ◽  
Control Measures ◽  
Effective Control ◽  
Diabetic Patients ◽  
History Of ◽  
And Gender ◽  
The Impact

Background Epidemiological features characterization of COVID-19 is highly important for developing and implementing effective control measures. In Saudi Arabia mortality rate varies between 0.6% to 1.26%. The purpose of the study was to investigate whether demographic characteristics (age and gender) and non-communicable diseases (Hypertension and Diabetes mellitus) have a significant association with mortality in COVID-19 patients. Methods Prior to data collection, an expedite approval was obtained from Institutional Review Board (IRB Log No: RC. RC20.09.10) in Al Habib Research Center at Dr. Sulaiman Al-Habib Medical Group, Riyadh, Saudi Arabia. This is a retrospective design where we used descriptive and inferential analysis to analyse the data. Binary logistic regression was done to study the association between comorbidities and mortality of COVID-19. Results 43 (86%) of the male patients were non-survivors while 7 (14%) of the female patients were survivors. The odds of non-survivors among hypertensive patients are 3.56 times higher than those who are not having a history of Hypertension (HTN). The odds of non-survivors among diabetic patients are 5.17 times higher than those who are not having a history of Diabetes mellitus (DM). The odds of non-survivors are 2.77 times higher among those who have a history of HTN and DM as compared to those who did not have a history of HTN and DM. Conclusions Those patients that had a history of Hypertension and Diabetes had a higher probability of non-survival in contrast to those who did not have a history of Diabetes and hypertension. Further studies are required to study the association of comorbidities with COVID-19 and mortality.

scholarly journals Geostatistical Model for the Arab-D Reservoir, North ’Ain Dar Pilot, Ghawar Field, Saudi Arabia: An Improved Reservoir Simulation Model

GeoArabia ◽  
1996 ◽  
Vol 1 (2) ◽  
pp. 267-284
Author(s):  
John L. Douglas ◽  
Keyword(s):  
Saudi Arabia ◽  
Fluid Flow ◽  
Reservoir Rock ◽  
Well Test ◽  
Geostatistical Model ◽  
Deterministic Models ◽  
Modeling Approach ◽  
The North ◽  
Porosity And Permeability ◽  
Ghawar Field

ABSTRACT The North ‘Ain Dar 3-D geocellular model consists of geostatistical models for electrofacies, porosity and permeability for a portion of the Jurassic Arab-D reservoir of Ghawar field, Saudi Arabia. The reservoir consists of a series of shallow water carbonate shelf sediments and is subdivided into 10 time-stratigraphic slices on the basis of core descriptions and gamma/porosity log correlations. The North ‘Ain Dar model includes an electrofacies model and electrofacies-dependent porosity and permeability models. Sequential Indicator Simulations were used to create the electrofacies and porosity models. Cloud Transform Simulations were used to generate permeability models. Advantages of the geostatistical modeling approach used here include: (1) porosity and permeability models are constrained by the electrofacies model, i.e. by the distribution of reservoir rock types; (2) patterns of spatial correlation and variability present in well log and core data are built into the models; (3) data extremes are preserved and are incorporated into the model. These are critical when it comes to determining fluid flow patterns in the reservoir. Comparison of model Kh with production data Kh indicates that the stratigraphic boundaries used in the model generally coincide with shifts in fluid flow as indicated by flowmeter data, and therefore represent reasonable flow unit boundaries. Further, model permeability and production estimated permeability are correlated on a Kh basis, in terms of vertical patterns of distribution and cumulative Kh values at well locations. This agreement between model and well test Kh improves on previous, deterministic models of the Arab-D reservoir and indicates that the modeling approach used in North ‘Ain Dar should be applicable to other portions of the Ghawar reservoir.

scholarly journals Awareness of COVID-19 Before and After Quarantine Based on Crowdsourced Data From Rabigh City, Saudi Arabia: A Cross-Sectional and Comparative Study

2021 ◽  
Vol 9 ◽  
Author(s):  
Mai Aldhahri ◽  
Rana Alghamdi
Keyword(s):  
Saudi Arabia ◽  
Online Survey ◽  
Control Measures ◽  
Infection Prevention And Control ◽  
Cross Sectional ◽  
Second Stage ◽  
Before And After ◽  
Prevention And Control Measures ◽  
Two Stages ◽  
And Control

Background: Infection prevention and control measures are critical for the prevention of the spread of COVID-19.Aim: In this study, we aimed to measure and evaluate the level of awareness and knowledge of the prevention, symptoms, and transmission control of COVID-19 before and after quarantine among the residents of Rabigh city and adjacent villages in Saudi Arabia.Methods: A cross-sectional online survey was conducted in two stages: the first stage took place before quarantine and the second stage took place after quarantine. The survey was filled out electronically.Results: A total of 448 participants responded and filled out the questionnaires. Females (73.70%) formed the largest number of participants for both stages. The majority of the participants were &lt;30 years old (50.90%) and had a high education level in various sectors and levels (97.1%). It was noticeable that during the first stage, the participants' awareness of COVID-19 symptoms was not very high: 13.62% did not know about the symptoms. However, by the second stage, awareness about symptoms had increased (9.6%).Conclusion: The residents of Rabigh city and the surrounding villages had good levels of knowledge about COVID-19.

Case Study of Identifying and Minimizing Formation Damage in Tight Reservoirs Caused by Drilling Fluids in Abu Dhabi Onshore Operation Using Compatibility Coreflood Studies

2021 ◽  
Author(s):  
Raymond Saragi ◽  
Mohammad Husien ◽  
Dalia Salim Abdullah ◽  
Ryan McLaughlin ◽  
Ian Patey ◽  
...  
Keyword(s):  
Positive Impact ◽  
Abu Dhabi ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Hydrocarbon Recovery ◽  
Tight Reservoirs ◽  
Filtrate Loss ◽  
Drilling Muds ◽  
Loss Control

Abstract A study was carried out to examine formation damage mechanisms caused by drilling fluids in tight reservoirs in several onshore oil fields in Abu Dhabi. Three phases of compatibility corefloods were carried out to identify potential to improve hydrocarbon recovery and examine reformulated/alternate drilling muds and treatment fluids. Interpretation was aided by novel Nano-CT quantifications and visualisations. The first phase examined the current drilling muds and showed inconsistent filtrate loss control alongside high levels of permeability alteration. These alterations were caused by retention of drilling mud constituents in the near-wellbore and incomplete clean-up of drilling mud-cakes. Based upon these results, reformulated and alternate drilling muds were examined in Phase 2, and there was a positive impact upon both filtrate loss and permeability, although the Nano-CT quantifications and visualisations showed that drilling mud constituents were still having an impact upon permeability. Candidate treatment fluids were examined in Phase 3, with all having a positive impact and the best performance coming from 15% HCl and an enzyme-based treatment. The interpretative tools showed that these treatments had removed drilling mud-cakes, created wormholes, and bypassed the areas where constituents were retained. The compatibility corefloods on tight reservoir core, alongside high-resolution quantifications and visualisations, therefore identified damaging mechanisms, helped identify potential to improve hydrocarbon recovery, and identify treatment fluid options which could be used in the fields.

Basin-wide rock-physics analysis in Campeche Basin, Gulf of Mexico — Phase II: Reservoir rock and fluid properties

2021 ◽  
Vol 40 (10) ◽  
pp. 716-722
Author(s):  
Yangjun (Kevin) Liu ◽  
Michelle Ellis ◽  
Mohamed El-Toukhy ◽  
Jonathan Hernandez
Keyword(s):  
Oil And Gas ◽  
Rock Physics ◽  
Clay Content ◽  
American Petroleum Institute ◽  
P Wave ◽  
Reservoir Rock ◽  
Gas Oil ◽  
Amplitude Variation With Offset ◽  
Fluid Properties ◽  
The Impact

We present a basin-wide rock-physics analysis of reservoir rocks and fluid properties in Campeche Basin. Reservoir data from discovery wells are analyzed in terms of their relationship between P-wave velocity, density, porosity, clay content, Poisson's ratio (PR), and P-impedance (IP). The fluid properties are computed by using in-situ pressure, temperature, American Petroleum Institute gravity, gas-oil ratio, and volume of gas, oil, and water. Oil- and gas-saturated reservoir sands show strong PR anomalies compared to modeled water sand at equivalent depth. This suggests that PR anomalies can be used as a direct hydrocarbon indicator in the Tertiary sands in Campeche Basin. However, false PR anomalies due to residual gas or oil exist and compose about 30% of the total anomalies. The impact of fluid properties on IP and PR is calibrated using more than 30 discovery wells. These calibrated relationships between fluid properties and PR can be used to guide or constrain amplitude variation with offset inversion for better pore fluid discrimination.

scholarly journals Immunological Factors Associated with Adult Asthma in the Aseer Region, Southwestern Saudi Arabia

2019 ◽  
Vol 16 (14) ◽  
pp. 2495 ◽  
Author(s):  
Al-Ghamdi ◽  
Koshak ◽  
Omer ◽  
Awadalla ◽  
Mahfouz ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Bronchial Asthma ◽  
Immunoglobulin E ◽  
Environmental Control ◽  
Complete Blood Count ◽  
Control Measures ◽  
House Dust Mites ◽  
Factors Associated ◽  
Immunological Factors ◽  
Age And Sex

Background: The prevalence of asthma is on the rise in Saudi Arabia. Data regarding the immunological profile of asthma in adults in the Aseer region, in southwestern Saudi Arabia, have not been well studied. Objectives: Our aim was to study the immunological factors associated with sensitization to asthma among adults in the Aseer region. Methods: A cross-sectional study with a nested case control design in a 1:1 ratio was conducted on a sample of adults attending primary health care centers in the Aseer region. The study used a validated Arabic version of the International study of asthma and allergies in childhood (ISAAC) questionnaire. The presence of wheezing in the past 12 months was used as a proxy for bronchial asthma. Matched age and sex controls were selected. Both groups were tested for complete blood count (CBC), total and differential white blood cell (WBC) count including eosinophils, total immunoglobulin E (IgE) measurement, allergen-specific immunoglobulin E (IgE), and cytokine levels. Results: The present study included 110 cases and 157 age- and sex-matched controls. Rye wheat was found to be a significant outdoor sensitizing agent ((odds ratio) OR = 5.23, 95% CI: 1.06–25.69). Indoors, house dust mites Dermatophagoides petronyssinus (OR = 2.04, 95% CI: 1.04–3.99) and Dermatophagoides farinae (OR = 2.50, 95% CI: 1.09–5.75) were significant. Higher total IgE (OR = 1.84, 95% CI: 1.10–3.06) and eosinophil levels (OR = 2.85, 95% CI: 1.14–7.15) were significantly associated with adult bronchial asthma in Aseer. On the other hand, the role of cytokines was not significant. Conclusions: In the present study, certain environmental agents were found to be important with regards to sensitization to bronchial asthma in adults. Knowledge about these sensitization agents should be disseminated to health providers and treating physicians in order to enhance preventive environmental control measures and asthma management. Asthma-treating physicians in the region should be alerted to the use of targeted biological therapies in selected asthmatics with difficult-to-control courses.

scholarly journals Experimental study on thermal, rheological and filtration control characteristics of drilling fluids: effect of nanoadditives

2020 ◽  
Vol 75 ◽  
pp. 36
Author(s):  
Erfan Veisi ◽  
Mastaneh Hajipour ◽  
Ebrahim Biniaz Delijani
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Drilling Fluid ◽  
Formation Damage ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Drill Bit ◽  
Rheological Characteristics ◽  
Cu Nanoparticles ◽  
Water Based

Cooling the drill bit is one of the major functions of drilling fluids, especially in high temperature deep drilling operations. Designing stable drilling fluids with proper thermal properties is a great challenge. Identifying appropriate additives for the drilling fluid can mitigate drill-bit erosion or deformation caused by induced thermal stress. The unique advantages of nanoparticles may enhance thermal characteristics of drilling fluids. The impacts of nanoparticles on the specific heat capacity, thermal conductivity, rheological, and filtration control characteristics of water‐based drilling fluids were experimentally investigated and compared in this study. Al2O3, CuO, and Cu nanoparticles were used to prepare the water-based drilling nanofluid samples with various concentrations, using the two-step method. Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD) were utilized to study the nanoparticle samples. The nanofluids stability and particle size distribution were, furthermore, examined using Dynamic Light Scattering (DLS). The experimental results indicated that thermal and rheological characteristics are enhanced in the presence of nanoparticles. The best enhancement in drilling fluid heat capacity and thermal conductivity was obtained as 15.6% and 12%, respectively by adding 0.9 wt% Cu nanoparticles. Furthermore, significant improvement was observed in the rheological characteristics such as the apparent and plastic viscosities, yield point, and gel strength of the drilling nanofluids compared to the base drilling fluid. Addition of nanoparticles resulted in reduced fluid loss and formation damage. The permeability of filter cakes decreased with increasing the nanoparticles concentration, but no significant effect in filter cake thickness was observed. The results reveal that the application of nanoparticles may reduce drill-bit replacement costs by improving the thermal and drilling fluid rheological characteristics and decrease the formation damage due to mud filtrate invasion.

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