EFFECT OF MICRITE CONTENT ON CALCITE CEMENTATION IN AN UPPER JURASSIC CARBONATE RESERVOIR,EASTERN SAUDI ARABIA

Cementation is a primary factor reducing the porosity of carbonate rocks. It is a challenge to accurately model cementation for reservoir quality prediction because cementation is often a syndepositional process. In addition, cementation requires fluid flow to transport chemical species for precipitation within the pore spaces in a sediment. The development of fully‐coupled depositional‐hydrogeochemical models for cementation prediction is desirable, but the parameters which control the extent of cementation need to be identified and evaluated. This study uses petrographic data from 583 carbonate samples from 15 wells in an Upper Jurassic (Kimmeridgian) reservoir at a giant oilfield in eastern Saudi Arabia to investigate the controlling effects of micrite content on cementation in carbonate rocks. The results indicate that the amount of cement decreases with increasing micrite content in the carbonate rocks analysed. In addition, a modified Houseknecht method has been developed to assess the relative fractions of porosity reduction in carbonate sediments due to compaction and cementation. The method highlights variations in depositional porosity for different rock textures and distinguishes microporosity from interparticle porosity. In the studied samples, the total porosity loss due to compaction and cementation is generally less than 45%, and samples lose more porosity due to compaction than cementation. The relative importance of compaction and cementation in reducing porosity is different for different rock textures: wackestones and mudstones lose porosity mostly as a result of compaction, while grainstones, mud‐lean packstones and packstones lose porosity due to both compaction and cementation.     

Natural Aggregates at Makkah Governate, Western Saudi Arabia

 Natural coarse and fine aggregates which accumulated along six selected wadis in the region of Makkah were assessed both qualitatively and quantitatively. The six wadis were Numan, Al-Yamanyah, Al-Shamyah, Hwarah, Alaf and Faydah. More than 440 aggregate samples were collected and their physical, mechanical and chemical properties determined. Petrographic studies on the gravel samples were undertaken to characterise the aggregate types. The results were compared with ASTM and British Standard specifications. The aggregates were generally within the acceptable limits for use in concrete although there were the relatively high values of chloride, sulphate and total dissolved salts in the fine aggregates in Wadis Alaf, Hwarah and Faydah. Nine fine aggregate samples representing upstream, midstream and downstream deposits from these saline wadis were washed in distilled waters after which the aggregates were within the acceptable limits for structural concrete. There were indications of material which could cause alkali-silica in the coarse aggregate at Wadi Faydah. The study proved reserves of 12.5 million m³ of coarse aggregate and 23 million m³ of fine aggregate. Received: 27 May 1998 · Accepted: 18 February 1999     

Modelling of weather characteristics and wind power in the eastern part of Saudi Arabia

In this work, the weather conditions and wind power in the eastern part of Saudi Arabia over a period of 36 years (1961–1996) are studied and modelled. The study involves temperature, relative humidity, fog, wind speed, wind power and dust storms. A regression analysis is carried out by using the linear regression technique to model the weather parameters. The models developed can be used in any study related to weather and its effect on the environment and energy. Copyright © 1999 John Wiley & Sons, Ltd.     

沙特阿拉伯天然气资源与利用现状

介绍了沙特阿拉伯丰富的天然气资源状况、其国家天然气系统(MGS)的建设情况,以及天然气利用现状和今后发展。该国在天然气利用方面的发展主要表现为：一是扩大天然气作为石油化工原料的利用,进一步发展石油化工;二是发展“天然气发展核心计划”,未来5年将有8家国际石油公司投资进行天然气勘探、生产和利用。     

沙特B区块高效破岩钻井技术

沙特B区块为典型的高温高压低孔低渗砂岩储层,平均机械钻速2.25 m/h,平均钻井周期250 d。为了提高机械钻速,缩短钻井周期,进行了沙特B区块高效破岩技术研究与应用。根据建立的沙特B区块岩石可钻性剖面,以岩石可钻性为基础,不同类型钻头的现场实钻效果为依据,与钻头厂家共同研究优选出了该区块不同地层的钻头推荐方案;参照沙特B区块地层的可钻性,根据螺杆钻具和涡轮钻具工作特征参数,优选出了适用于该区块的螺杆钻具和涡轮钻具。现场应用表明,沙特B区块采用优选出的钻头推荐方案“螺杆钻具+PDC钻头”和“涡轮钻具+孕镶金刚石钻头”复合钻井方式可以实现高效破岩,使该区块平均机械钻速提高46.8%,钻井周期缩短23.3%。      

Biogas production from municipal sewage sludge (MSS)

Biogas is produced by anaerobic (oxygen free) digestion of organic materials such as sewage sludge, animal waste, and municipal solid wastes (MSW). As sustainable clean energy carrier biogas is an important source of energy in heat and electricity generation, it is one of the most promising renewable energy sources in the world. Biogas is produced from the anaerobic digestion (AD) of organic matter, such as manure, MSW, sewage sludge, biodegradable wastes, and agricultural slurry, under anaerobic conditions with the help of microorganism. Biogas is composed of methane (55–75%), carbon dioxide (25–45%), nitrogen (0–5%), hydrogen (0–1%), hydrogen sulfide (0–1%), and oxygen (0–2%). The sewage sludge contains mainly proteins, sugars, detergents, phenols, and lipids. Sewage sludge also includes toxic and hazardous organic and inorganic pollutants sources. The digestion of municipal sewage sludge (MSS) occurs in three basic steps: acidogen, methanogens, and methanogens. During a 30-day digestion period, 80–85% of the biogas is produced in the first 15–18 days. Higher yields were observed within the temperature range of 30–60°C and pH range of 5.5–8.5. The MSS contains low nitrogen and has carbon-to-nitrogen (C/N) ratios of around 40–70. The optimal C/N ratio for the AD should be between 25 and 35. C/N ratio of sludge in small-scale sewage plants is often low, so nitrogen can be added in an inorganic form (ammonia or in organic form) such as livestock manure, urea, or food wastes. Potential production capacity of a biogas plant with a digestion chamber size of 500 m³ was estimated as 20–36 × 10³ Nm³ biogas production per year.     

沙特阿美2011年业务发展简况

简要分析了沙特阿美公司2011年上游、下游及贸易业务的发展情况及2020发展战略。     

Linking project health to project performance indicators: Multiple case studies of construction projects in Saudi Arabia

This research presents an empirical study of the relationship between project health and project performance in the project delivery context. Based on an existing Project Health Check (PHC) framework, the relationship has been tested in terms of a set of predefined indicators through the use of case study approach. The Swiss Cheese model was employed as a guiding principle to represent the links between PHC indicators and project Key Performance Indicators (KPIs). Three cases of construction projects in Saudi Arabia were investigated through a comprehensive review of the project performance history, using current performance indicators to establish the first slice of the Swiss Cheese model. PHC assessments were then conducted to shape the second slice of the model, which represent the maturity level of the project management. The relationships between the two slices were obtained from semi-structured interviews with the project managers. These relationships were analysed qualitatively by tracking patterns across the three cases. The result was used to develop the Swiss Cheese Performance Management Framework, which can potentially serve to help project managers identify the root causes of any shortcomings at the early stage in the project delivery process. This in turn can assist project managers in managing the overall project performance more effectively.