Testing of Saudi Shales for Potential Use in Drilling Fluids

This paper presents the results of rheological, electrochemical and filtration analyses of Umm-er-Radhuma shales in Saudi Arabia. The analyses indicate that these shales could be used as a basic constituent of drilling fluids. A preliminary assessment of the raw material future requirements in the drilling operations in Saudi Arabia is made.The mineralogical and chemical analyses of Umm-er- Radhuma shales showed the presence of palygorskite in these sediments. These shales consisted of more than 95% clay size particles most of which were less than 0.2 μm in size. The rheological behavior of palygorskite based fluids have been studied with and without the addition of chlorides and/or hydroxides of Na, K, Ca and Mg. The changes in the rheological properties have been correlated with the mineralogy of the used clays.It is believed that Saudi Arabia will invest huge sums of money to increase its oil production capacity in order to meet the expected oil demand increase in the 90s. Drilling activities will consume a big share of the investment. It is found that, the use of Umm er Radhuma natural resources in the drilling of oil and water wells in Saudi Arabia will save millions of dollars that otherwise would have to be spent on importing the raw materials from elsewhere

Applications of the Enhanced Recovery Methods to Saudi Oil Fields

Based on the analysis of data obtained from 186 Saudi formations, the possibilities of applying different enhanced oil recovery (EOR) methods were investigated.It was found that the most suitable technical methods applicable to Saudi oil fields are the miscible processes using gases. A new technology should be developed in order to be able to apply any of the enhanced recovery methods involving chemicals and heat. A study of the economical feasibility of these methods should also be performed

Laboratory and economic study on Saudi oil recovery by Alkaline flooding

Oil displacements in Saudi sandstone and limestone cores were performed. Some runs were carried out in Berea sandstone cores at different temperatures from 22 to 60°c. Safaniya crude oil (obtained from Safaniya oil field operated by Saudi Aramco) was used in displacement tests. Economical application of the process was studied 10 evaluate oil/recovery. Safaniya crude was determined to be acidic. Alkaline concentration reduces brine interfacial tension with an optimum value at about 0.5 percent. Oil recovery was greater in limestone cores. Increasing temperature from 25 to 60° improved displacement efficiency. The economical feasibility study indicated that initial oil saturation in the reservoir, price of injected NaOH and oil price have an effect on the decision of applying the process of enhanced alkaline flooding

Laboratory and Economic Study on Saudi Oil Recovery by Alkaline Flooding

Oil displacements in Saudi sandstone and limestone cores were performed. Some runs were carried out in Berea sandstone cores at different temperatures from 22 to 60°C. Safaniya crude oil (obtained from Safaniya oil field operated by Saudi Aramco) was used in displacement tests. Economical application of the process was studied to evaluate oil/recovery. Safaniya crude was determined to be acidic. Alkaline concentration reduces brine interfacial tension with an optimum value at about 0.5 percent. Oil recovery was greater in limestone cores. Increasing temperature from 25 to 60° improved displacement efficiency. The economical feasibility study indicated that initial oil saturation in the reservoir, price of injected NaOH and oil price have an effect on the decision of applying the process of enhanced alkaline flooding

Testing of saudi shales for potential use in drilling fluids

Petroleum Engineering Department, College of Engineering, King Saud UniversityThis paper presents the results of rheological, electrochemical nnd filtration analyses of Umm-er-Radhuma shales in Saudi Arabia. The analyses indicate that these shales could be used as a basic con-stituent of drilling fluids. A preliminary assessment of the raw material future requirements in the drilling operations in Saudi Arabia is made. The mineralogical and chemical analyses of Umm-er- Radhuma shales showed the presence of palygorskite in these sediments. These shales consisted of more than 95% clay size particles most of which were less than 0.2 ~m in size. The rheological behavior of palygorskite based fluids have been studied with and without the addition of chlorides and/or hydroxides ofNa, K, Ca and Mg. The changes in the rheolog-ical properties have been correlated with the mineralogy of the used clays. It is believed that Saudi Arabia will invest huge sums of money to increase its oil production capacity in order to meet the expected oil demand increase in the 90s. Drilling activities will consume a big share of the investment. It is found that, the use of Umm er Radhuma natural resources in the drilling of oil and water wells in Saudi Arabia will save millions of dollars that otherwise would have to be spent on importing the raw materials from elsewhere

Possible Applications of MEOR to the Arab Oil Fields

Large quantities of residual oil will remain in the Arab oil reservoirs after the primary recovery and water-flooding stages. Because of the large sizes of the Saudi oil fields (in particular), the amount of the residual oil will be enormous. According to the latest published data, the original oil in-place in Saudi Arabia is about 700 billion barrels. Only around 250 billion barrels, 35% of total oil in-place, can be produced by conventional production methods. More than 90 billion barrels, as much as twice the proven reserve of the U.S. and Canada combined, can be added to the country’s proven reserve if only 20% out of the 450 billion barrels left in-place are produced through enhanced oil recovery methods. Any method that can recover a significant part of this residual oil would be of great importance and should be investigated. Microbial Enhanced Oil Recovery (MEOR) has been recognized as a potentially cost-effective recovery method.This paper is an investigation of the applicability of MEOR for recovering more oil under the Arab oil fields conditions. Based on the analysis of data obtained from more than 300 formations in seven Arab countries (Saudi Arabia, Egypt, Kuwait, Qatar, UAE, Iraq and Syria), the possibility of the application of MEOR to the Arabian area was studied. The basic parameters studied include formation permeability, reservoir pressure and temperature, crude oil viscosity and API gravity, formation connate water saturation and its salinity. It was found that Saudi, Iraqi and Egyptian oil fields can be very good candidates for MEOR processes. Also Qatar, Kuwait and Syria have some potential for MEOR. United Arab Emirates, however, has no potential for MEOR under its reservoir conditions.It is expected that MEOR should recover up to 30% of the residual oil under the Arab reservoir conditions. The actual recovery, however, can only be determined through laboratory and pilot tests under field conditions. A new technology should be developed in order to be able to apply MEOR succesfully

Testing of Saudi Sandstones for Potential Use in Hydraulic Fracturing of Hydrocarbon Reservoirs

This paper presents the results of testing four Saudi sandstone containing formations namely; Dammam, Al-Biyad and Al-Wassia, Al-Manjour, and Durma to be used as propping agents for hydraulic fracturing operations. A review of Saudi oil reservoirs showed that about 35% of these reservoirs have permeabilities lower than 0.05 darcy and may need hydraulic fracturing operations in the future to increase oil productivity.The analysis showed that the Saudi sandstones are friable and composed mainly of quartz. The sands can produce four proppant mesh sizes: 30/50, 40/70, 60/120 and 70/140, which are common in hydraulic fracturing operations. The physical properties meet or exceed the recommended API values. The proppants produced from Dammam and Al-Manjour sands can be used in hydraulic fracturing with acid attack. The other proppants are to be used in hydraulic fracturing without acid attack. Also, the proppant mesh sizes are to be recommended for fracturing shallow and medium depth Saudi reservoirs, depth down to 8000 feet, and can be produced economically

Bacterial Isolate from Arabian Gulf Coast Soils in Saudi Arabia Able to Degrade Arab Crude Oil

By means of the enrichment culture technique, two types of microorganisms were isolated from oil contaminated soil samples gathered from coastal area of Saudi Arabia on the Arabian Gulf. One bacterial isolate has proved its ability to degrade Arab crude oil added to aqueous phases (salts solution, sterile and nonsterile Gulf water) while the other failed to adapt itself in salts solution. The active species was identified as Pseudomonas sp. About 80% of Arab crude oil added to salts solution and nonsterile Gulf water had disappeared within 10 days of incubation by this active isolate. Nonsterile Gulf water yielded higher degradation per cent than sterile Gulf water because of the activation of the indigenous flora and the sufficiency of organic and inorganic nutrients. The bacteria proved optimum degradation per cent at 25 L and 2.5 mg/ml Arab crude oil concentration. Adding nutrients activated the degradation process and phosphorus has proved the best rate among other nutrients. Increasing the inoculum size of bacteria in the presence of sufficient nutrients directly affected the biodegradation per cent of Arab oil added to an aqueous phase

Nuclear Magnetic Resonance Log Evaluation of Low-Resistivity Sandstone Reservoirs by-Passed by Conventional Logging Analysis

The combination of conventional logs such as density, neutron and resistivity logs is proven to be very effective in the evaluation of normal reservoirs. For low resistivity reservoirs, however, an accurate determination of the petrophysical parameters with the conventional log reservoirs is very difficult. This paper presents two cases of low resistivity reservoirs and low contrast resistivity reservoirs where conventional logs fail to determine the petrophysical properties of reservoirs, mainly, low resistivity and low contrast resistivity reservoirs. The problems of these reservoirs is that conventional logging interpretation shows high water saturation zones, but water free hydrocarbon would be produced. In the case of low resistivity contrast reservoirs it is very hard to determine water hydrocarbon contact with resistivity logs. Nuclear magnetic resonance (NMR) has been only available as a supplement tool, to provide additional information on the producibility of the reservoir. The main limitation of NMR, however, has been the cost and time of acquiring data. This paper shows that in the case of low resistivity reservoirs NMR is very cost-effective tool and helps to accurately determine the reservoir rock petrophysical properties. In the analysis of NMR data, several aspects of NMR technique have been used; 1) T1/T2 ratio for fluid identification, 2) the difference between NMR derived porosity and total porosity to determine the types of clay minerals, 3) NMR relaxation properties to identify fluids nature and rock properties. This paper presents four examples of low resistivity reservoirs. Analysis of NMR data of low resistivity reservoirs has helped to identify the producibility of these zones, to determine lithology independent porosity and to distinguish between bound and free water. For the case of low contrast resistivity reservoir where there was little resistivity contrast between water bearing formation and oil bearing formation, NMR has been able to identify the fluid nature of the two formations and then the height of the oil column. This was based mainly on high contrast of NMR relaxation parameters.King Saud Universit

Nuclear magnetic resonance log evaluation of low-resistivity sandstone reservoirs

The combination of conventional logs such as density, neutron and resistivity logs is proven to be very effective in the evaluation of normal reservoirs. For low resistivity reservoirs, however, an accurate determination of the petrophysical parameters with the conventional logs reservoirs is very difficult. This paper presents two cases of low resistivity reservoirs and low contrast resistivity reservoirs where conventional logs fail to determine the petrophysical properties of reservoirs, mainly, low resistivity and low contrast resistivity reservoirs. The problems of these reservoirs is that conventional logging interpretation shows high water saturation zones, but water free hydrocarbon would be produced. In the case of low resistivity contrast reservoirs it is very hard to determine water hydrocarbon contact with resistivity logs. Nuclear magnetic resonance (NMR) has been only available as a supplement tool, to provide additional information on the producibility of the reservoir. The main limitation of NMR, however, has been the cost and time of acquiring data. This paper shows that in the case of low resistivity reservoirs NMR is very cost-effective tool and helps to accurately determine the reservoir rock petrophysical properties. In the analysis of NMR data, several aspects of NMR technique have been used; 1) T1/T2 ratio for fluid identification, 2) the difference between NMR derived porosity and total porosity to determine the types of clay minerals, 3) NMR relaxation properties to identify fluids nature and rock properties. This paper presents four examples of low resistivity reservoirs. Analysis of NMR data of low resistivity reservoirs has helped to identify the producibility of these zones, to determine lithology independent porosity and to distinguish between bound and free water. For the case of low contrast resistivity reservoir where there was little resistivity contrast between water bearing formation and oil bearing formation, NMR has been able to identify the fluid nature of the two formations and then the height of the oil column. This was based mainly on high contrast of NMR relaxation parameters.King Saud Universit