Down-hole temperature

A drilling fluid additive, which acts as a clay stabilizer, is the reaction product of methylglucoside and alkylene oxides such as ethylene oxide, propylene oxide, or butylene oxide. Such an additive is soluble in water at ambient conditions, but becomes insoluble at elevated down-hole temperatures [386], Because of their insolubility at elevated temperatures, these compounds concentrate at important surfaces such as the drill bit cutting surface, the borehole surface, and the surfaces of the drilled cuttings. 

In situ NMR measurements can be made in conjunction with down-hole fluid sampling [5, 6]. The NMR relaxation time and diffusivity can be measured under high-temperature, high-pressure reservoir conditions without loss of dissolved gases due to pressure depletion. In cases when the fluids may be contaminated by invasion of the filtrate from oil-based drilling fluids, the NMR analysis can determine when the fluid composition is approaching that of the formation [5, 6]. 

Most sampling takes place at the wellhead rather than down-hole. The fluids are therefore subjected to major reductions in temperature and pressure, to gas loss and to exposure to oxidizing conditions during sampling. The special methods that must be used in sample collection, preservation, and field and laboratory determinations of chemical components and isotopes in formation waters are detailed in Lico et al. (1982) and Kharaka et al. (1985). 

Conversely where less stringent thermal demands are appropriate, choices are broadened to encompass materials more commonly referred to as "commodity resins". Ultimate end product operational environments will impact the material selection process. Where in-service temperatures range from room ambient to moderate thermal extremes, lesser thermally tolerant resins may be considered. Conversely, for hostile environments such as those encountered in "under the hood" automotive, down-hole (geothermal), tropical, or corrosive climatic axtremes, enhanced material properties will be required. 

A down-hole safety valve (DSV) is located underground. This is a self-contained valve that operates on high flow and does not require external signals or power for its operation. The valve is normally open, and closes automatically when its differential pressure reaches a predetermined value. Based on the flowing capabilities of the well, each valve is adjusted to accommodate the fluid, pressure, temperature and flow rate of the well. 

Several groups have also demonstrated adequate performance at normal room temperatures and this allows the technology to address the large and ever-growing market in portable electronic devices. In these applications, the performance characteristics will be augmented by the ability to fabricate batteries into a variety of shapes and sizes. There are also a number of specialized applications which LPBs could address these include, for example. Smart Cards and down-hole batteries for the oil industry. 

Automated Dynamics Corporation have used PES and PEEK/carbon fiber thermoplastic prepreg for the manufacture of high temperature pipe and down hole components. 

It is used for down-hole packers and seals in oil exploration and production. Oilfield equipment seals are exposed to short-term temperatures from 302 to 482°F (150 to 250°C) and pressures above 10,000 Ib/in (68.7 MPa) in the presence of aggressive hydrocarbons H2S, CH4, CO2, amine-containing corrosion inhibitors, and steam and water. 

Silicon (Si). The electronic transport is due exclusively to electrons in the [100] conduction band minima and holes in the two uppermost (heavy and light) valence bands. In samples with impurity concentrations below 10 cm , the mobilities are determined by pure lattice scattering down to temperatures of about 10 K (n-type) or 50 K (p-type), for electrons and holes, respectively. Higher impurity concentrations lead to deviations from the lattice mobility at corresponding higher temperatures. For electrons, the lattice mobility below 50 K is dominated by deformation-potential coupling... 

The down-hole oil and gas environment is especially challenging. Conditions vary from well to well but usually involve a corrosive, high temperature environment with a multitude of organic and possibly inorganic components in the fluid being removed from the well. During operation of the well, various substances may precipitate on... 

High-Temperature Cells. Specially designed hermetically sealed batteries have been developed for use at the high temperatures encountered, for example, by the oil-well logging industry, which uses down-hole tools operating to 150°C, the maximum temperature at which the Li/CuO cells can operate. 

Oil well cements are required to fix steel casing to the drilled borehole wall, for down-hole repairs and to isolate zones in the formation. Set retarders are required to prevent premature setting while the cement is being pumped into place through high-temperature zones. In this application, borates are used as set retarders or assists for other retarders, such as lignosul-fonates, cellulosic derivatives, and synthetic polymers. They are effective retarders for OPC and other cements. 

The solubility product of salt changes with temperature and the concentration of the ions present in solution. In oilfield brines, if the surface solubility produced is smaller than their solubility product under down-hole formation, scale formation would occur. Under such conditions, the water is called unstable water. The StabiUty Index (S/) is used to predict the tendency of ions to form scales from oilfield brines which are highly corrosive and encountered during drilling process. The Stiff-Davis Modification of the Langelier equation is used to predict calcium carbonate precipitation from the brines and is given by... 

Control of BM Reaction Temperature Under Down Hole... 

CONTROL OF BM REACTION TEMPERATURE UNDER DOWN HOLE AND RESERVOIR CONDITIONS... 

Industrial markets PPA resin has a wide range of features that make it useful for various industrial applications. For example, its superior impact resistance, especially at sub-zero temperatures, combined with its good chemical resistance in down-hole environments, makes it an excellent choice for oil well drilling components. 

Barium sulfate solubihty increases with temperature and because of this, barium sulfate usually presents no down-hole scaling problems in an injection well if it is non-scaling at surface conditions. It is more commonly a problem in producing or source wells. 

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