The Problem of Determining Petroleum Reservoir Rock Wettability

1960 ◽  
Author(s):  
Charles G. Dodd
Keyword(s):  
Reservoir Rock ◽  
Petroleum Reservoir

Tandem scanning confocal light microscopy as compared with x-ray diffraction for characterizing the behavior of clays in fluid-saturated petroleum reservoir rock

1989 ◽  
Vol 47 ◽  
pp. 148-149
Author(s):  
C.J. Stuart ◽  
B.E. Viani ◽  
J. Walker ◽  
T.H. Levesque
Keyword(s):  
Light Microscopy ◽  
Image Plane ◽  
Reservoir Rock ◽  
Depth Of Field ◽  
Objective Lens ◽  
Scanning System ◽  
Light Sources ◽  
Petroleum Reservoir ◽  
Image Recording ◽  
Scan Speed

Many techniques of imaging used to characterize petroleum reservoir rocks are applied to dehydrated specimens. In order to directly study behavior of fines in reservoir rock at conditions similar to those found in-situ these materials need to be characterized in a fluid saturated state.Standard light microscopy can be used on wet specimens but depth of field and focus cannot be obtained; by using the Tandem Scanning Confocal Microscope (TSM) images can be produced from thin focused layers with high contrast and resolution. Optical sectioning and extended focus images are then produced with the microscope. The TSM uses reflected light, bulk specimens, and wet samples as opposed to thin section analysis used in standard light microscopy. The TSM also has additional advantages: the high scan speed, the ability to use a variety of light sources to produce real color images, and the simple, small size scanning system. The TSM has frame rates in excess of normal TV rates with many more lines of resolution. This is accomplished by incorporating a method of parallel image scanning and detection. The parallel scanning in the TSM is accomplished by means of multiple apertures in a disk which is positioned in the intermediate image plane of the objective lens. Thousands of apertures are distributed in an annulus, so that as the disk is spun, the specimen is illuminated simultaneously by a large number of scanning beams with uniform illumination. The high frame speeds greatly simplify the task of image recording since any of the normally used devices such as photographic cameras, normal or low light TV cameras, VCR or optical disks can be used without modification. Any frame store device compatible with a standard TV camera may be used to digitize TSM images.

A new technique utilizing Scanning Electron Microscopy at low temperature and voltage to analyze native-state reservoir rocks

1989 ◽  
Vol 47 ◽  
pp. 686-687
Author(s):  
C. J. Stuart ◽  
L.-C. Liang ◽  
J. B. Toney
Keyword(s):  
Solid State ◽  
Low Voltage ◽  
Thermal Contact ◽  
High Vacuum ◽  
Reservoir Rock ◽  
Petroleum Reservoir ◽  
Native State ◽  
Analytical Technique ◽  
Reservoir Rocks ◽  
Scanning Electron

A new analytical technique has been developed to allow direct imaging of native-state petroleum reservoir rocks by the use of the scanning electron microscope (SEM) in a low voltage mode combined with a solid-state cryo-system device. The SEM investigation of native-state reservoir rock samples is important since it enables direct visualization of: (1) the spatial distributions of the fluids in the pore system; (2) clay minerals in their natural hydrated states; (3) the native mineralogy; (4) combined effects on the reservoir's wettability and permeability. The technique uses low voltage SEM to image the uncoated surface of the wet sample at a high vacuum and applies the cryostage to control the vapor pressure of the fluid phase while imaging. A differentially pumped environmental chamber is not required with this approach.This technique utilizes a solid-state thermoelectric cooler device (TED) to achieve the required sample cooling. The TED operates on the Peltier principle permitting the surface of the TED to reach a temperature as low as 110 degrees centigrade below its reference temperature. A sample stage is refitted with a TED substage which is water-cooled. The water-cooling of the substage coupled with the TED allows a precise control of the sample temperature. The sample is fixed to the substage so that it is in direct thermal contact with the TED. The TED is then biased (by the use of DC currents) to provide the effective cooling necessary to minimize vaporization of the interstitial fluids in the sample. The sample and stage temperatures are constantly monitored by means of two microtype-K thermocouple devices. With this approach, no liquid nitrogen is needed for this technique.

SEDIMENTATION AND PETROLEUM POTENTIAL OF THE JURASSIC SEQUENCE IN THE SOUTHWESTERN GREAT ARTESIAN BASIN

1969 ◽  
Vol 9 (1) ◽  
pp. 97
Author(s):  
O. W. Nugent
Keyword(s):  
Reservoir Rock ◽  
Petroleum Reservoir ◽  
Petroleum Potential ◽  
Artesian Basin ◽  
Fine Grained ◽  
Great Artesian Basin ◽  
Facies Change ◽  
Area North ◽  
Sandstone Facies ◽  
Jurassic Sequence

Along the western margins of the southwestern Great Artesian basin the Jurassic sequence is an almost continuous sandstone section. In the eastern part of the same area, this sandstone sequence is broken by two shale-siltstone intervals, the Birkhead and Westbourne Formations. Towards the western margins of the basin these facies change into sandstone. The Murta Member of the Mooga Formation develops in the area north of Lake Frome through a facies change in the upper part of this formation from sandstone to siltstone and shale. It is postulated that the depositional conditions in the southwestern Great Artesian basin were dominantly fluviatile during most of the Jurassic and that the fine grained sediments of the Birkhead and Westbourne Formations and the Murta Member of the Mooga Formation were deposited under low energy lacustrine conditions. Abundant good quality potential petroleum reservoir rock exists throughout the entire Jurassic sequence. The lack of hydrocarbon filled traps found to date and the change of the main siltstone-shale intervals into sandstone facies in the west and southwest, imply that the Jurassic in the southwestern Great Artesian basin has been effectively flushed. However, the complex facies relationship of the sandstone and shale beds indicates that stratigraphically controlled traps may exist. The most prospective part of the Jurassic for commercial hydrocarbons appears to be in the lower part of the Hutton Sandstone.

A Liquid-Freon Permeameter

1962 ◽  
Vol 2 (01) ◽  
pp. 18-20
Author(s):  
B.G. Hurd
Keyword(s):  
Gas Permeability ◽  
Reservoir Rock ◽  
Explosion Hazard ◽  
Petroleum Reservoir ◽  
Laboratory Equipment ◽  
Reservoir Rocks ◽  
Rock Samples ◽  
Halogenated Hydrocarbon ◽  
Liquid Saturation ◽  
Gas Pressures

HURD, B.G., SOCONY MOBIL OIL CO., INC., DALLAS, TEX. Abstract A liquid-Freon permeameter suitable for making routine permeability determinations on small plug samples is described. The instrument is characterized by simplicity of design and ease of operation, and can be assembled inexpensively from stock items of laboratory equipment. It combines the unique advantages of both liquid and gas permeameters while eliminating many undesirable features of both general classes of instruments. Precision and accuracy of the specific Freon permeability measurements compare favorably with results of conventional liquid and gas permeameters. Introduction The liquid-Freon permeameter described in this paper was designed and built for special investigations of the properties of petroleum reservoir rocks. However, its unique advantages over conventional gas and liquid permeameters make it eminently suitable for routine use in the core analysis of small plug samples. In general, gas permeameters are very popular because of their simplicity of design and ease of operation. However, apparent gas permeabilities are normally higher than true specific permeabilities unless special corrections for gas-slippage are applied. Since these corrections require two or more measurements at different internal gas pressures, much of the time advantage of the specific gas permeability measurements is lost. Liquid permeability measurements, on the other hand, require no slip correction, but liquid saturation of the sample is time-consuming and difficult to insure. Often, too, the saturating liquid must be extracted or dried from the plug before it can be used for another experiment. The liquid Freon permeameter described herein retains the inherent accuracy of the liquid permeameter, while affording the speed and ease of operation of the gas permeameter. Freon-12 (dichlorodifluoromethane) is a halogenated hydrocarbon, immiscible in the liquid phase with water. It may be considered as an oil phase in laboratory fluid-flow studies. Like butane and propane, it is a gas at normal room temperatures and atmospheric pressure but can be liquefied at moderate pressures. Complete liquid saturation of a plug sample with any of these fluids can be easily achieved by condensing vapors in the sample and operating the permeameter at a pressure above the vapor pressure of the liquid. Freon-12 is superior to butane or propane for permeability measurements only in that it is relatively non toxic and completely incombustible, and thus presents no fire or explosion hazard. Freon-12 is believed to be completely nonreactive with most petroleum-reservoir rock samples. It volatilizes immediately from a plug on depressurizing to leave a clean, dry sample suitable for subsequent experiments. Thus, the inherent risk of changing physical properties of rock samples by cleaning and drying operations between permeability measurement and subsequent experiments is eliminated. DESCRIPTION OF THE PERMEAMETER The design of the liquid Freon permeameter is shown schematically in Fig. 1. SPEJ P. 18^

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