Temperature sandstone

Mixed acid systems are blends of mineral acids and organic acids. Combinations that have been used in carbonate acidizing include acetic acid/HCl and formic acid/HCl. While these are less corrosive than hydrochloric acid alone, the organic acid may not react completely with the rock. Blends of formic acid and hydrofluoric acid have been used in high temperature sandstone acidizing and are less corrosive than HC1/HF blends. 

The main component of sandstone reservoirs ( siliciclastic reservoirs ) is quartz (Si02). Chemically it is a fairly stable mineral which is not easily altered by changes in pressure, temperature or acidity of pore fluids. Sandstone reservoirs form after the sand grains have been transported over large distances and have deposited in particular environments of deposition. 

Shikazono and Shimizu (1987) concluded that Ag contents of gold precipitated from low-salinity fluids is higher than that prediction and the relationship between NAg of gold and salinity of fluid inclusions estimated from freezing temperature data. Therefore, another interpretation is that NAg of gold from shale-hosted deposits is lower than that from sandstone-hosted deposits, because shale is expected to be richer in Cl mainly due to adsorption by clay minerals included in shale than sandstone. 

Thus, log-log plots of S versus C provide an easy way to obtain the values for K (the intercept) and N (the slope of the line). The log-log plot can be used for graphic interpolation of adsorption at other concentrations, or, when values for K and N have been obtained, the amount of adsorption can be calculated from Equation 20.9. Figure 20.9 shows an example of adsorption isotherms for phenol adsorbed on Frio sandstone at two different temperatures. Note that when N = 1, Equation 20.9 simplifies to Equation 20.6 (i.e., adsorption is linear). 

FIGURE 44 Weathering. A weathered sandstone column. Calcite (composed of calcium carbonate) is dissolved by rain and groundwater (see Textbox 73). When stone in which calcite is a main component as, for example, sandstone, limestone, and marble, is in contact with water for long periods of time, it is weathered and partly or entirely dissolved. Pollutants such as sulfur dioxide are fundamental in accelerating the weathering and dissolution process. When sulfur dioxide, for example, dissolves in rainwater, it forms sulfuric acid, a strong acid that, at ambient temperatures, rapidly dissolves calcium carbonate. 

Oils The n-alkane series Cg-C, toluene and cyclohexane were purchased from BDH, Poole, UK, each with a stated purity of 99% reagents were used as received. Crude oil samples were obtained from two North Sea fields one located in the Norwegian sector and the other from the UK sector. Stock tank oil from the Gullfaks field was supplied by Statoil, Norway and the other stock tank oil from an undisclosed source. Both crude oils are derived from sandstone formations with reservoir temperatures of 70° and 101°C respectively. 

High pressure equipment has been designed to measure foam mobilities in porous rocks. Simultaneous flow of dense C02 and surfactant solution was established in core samples. The experimental condition of dense CO2 was above critical pressure but below critical temperature. Steady-state CC -foam mobility measurements were carried out with three core samples. Rock Creek sandstone was initially used to measure CO2-foam mobility. Thereafter, extensive further studies have been made with Baker dolomite and Berea sandstone to study the effect of rock permeability. 

To consider how such predictions might be made, we model how three types of alkali floods might affect a hypothetical sandstone reservoir. The floods, which are marketed commercially for this purpose, are NaOH, Na2C03, and Na2Si03. We take each flood at 0.5 N strength and assume that reaction occurs at a temperature of 70 °C. 

Sydansk, R. D., 1982, Elevated-temperature caustic/sandstone interaction, implications for improving oil recovery. Society of Petroleum Engineers Journal 22, 453 462. 

This process began many millions of years ago with the development of abundant life, and it continues to this day. The sediments grow thicker and sink into the sea floor under their own weight. As additional deposits pile up, the pressure on the ones below increases several thousand times, and the temperature rises by several hundred degrees. The mud and sand harden into shale and sandstone. Carbonate precipitates and skeletal shells harden into limestone. The remains of the dead organisms are then transformed into crude oil and natural gas. Usually the underground and formation pressure is sufficient for the natural release of hydrocarbon liquids and gases to the surface of the earth. 

A series of leaching experiments were carried out on mineralized sandstone and siltstone from the Green Street Occurrence (Parsons 2007). The samples were poorly consolidated and easily broken apart by hand and placed into the waters. The samples were placed in distilled water, stream water, and rain water at temperatures ranging from 5 to... 

Quartz occurs in granite, sand, crystals, and sandstone. Quartz also has several crystalline varieties such as purple amethyst, colorless rock crystal, and yellow citrine. Flint, agate, and chert, etc. are other forms of quartz. Quartz is an excellent insulator. It does not break under temperature changes because of its low coefficient of expansion. Fused quartz transmits ultraviolet light. 

The size of the reactors is quite variable. In length, the biggest reactor has dimensions of 12 x 18 m and has a thickness of 20 to 50 cm (Fig. la). The core of the reactors consists of a 5 to 20 cm thick layer of uraninite embedded in clays (illite and chlorite). Clays around the reactors result from the hydrothermal alteration of the host sandstone during the fission reactions. This alteration occurred at a temperature close to 400 °C in the core. Temperature decreased drastically toward the vicinity with a thermal gradient of 100 °C/m (Pourcelot Gauthier-Lafaye 1999). The uranium content of the core ranges between 40 and 60%. Accessory minerals are mainly sulphides (pyrite and galena), hematite and phosphates (mainly hydroxyapatite). 

At 10 MPa and 35 °C, C02 has a density of approximately 700kg/m3. Under these conditions, a cubic meter of sandstone with 10% porosity contains approximately 70 kg of C02 if the pore space is completely filled by C02. However, saturation of C02 is not complete, and some brine remains in the invaded pore spaces (Saripalli McGrail 2002 Pruess et al. 2003). In addition, non-uniform flow of C02 bypasses parts of the aquifer entirely. Darcy-flow based analytical and numerical solutions are used to evaluate some of these effects by simulating the advance of the C02 front over time-scales of decades to hundreds of years and over lateral distances of tens to hundreds of kilometers. To account for the extreme changes in density and viscosity of C02 with pressure and temperature, these models must incorporate experimentally constrained equations of state (Adams Bachu 2002). 

Temperature was set at 35 °C. Brine-rock mass ratio was set to 0.4 10, which corresponds to a porosity of approximately 10%. The mineral content and brine compositions were set to measured values (Table 1). Debyc-Hiickel equations were used to correct activity coefficients for saline solutions. The brine was allowed to come to equilibrium with the C02, then the 10 kg of sandstone was added and equilibrium assemblages were computed a second time. 

A piece of sandstone with a bulk volume of 1.3 cc is contained in a 5-cc cell filled with helium at 760 mm Hg. Temperature is... 

Geopressured Zones. A test well in a geopressure zone was drilled some years ago in Tigre Lagoon in the coastal marshes of southern Louisiana Known as Edna Delcambre 1, this well produced at a rate of np to 10,000 barrels of water per day from a sandstone aquifer some 12,600 feet (3840 meters) below the surface. Pressure at that depth is nearly 11,000 pounds per square inch (748 atmospheres) and the temperature is 116°C. Quite an elaborate manifold system is requited to collect the gas. The water is disposed by forcing it by... 

Procedures. Batch equilibrations of interbed solids (Mabton Interbed, Rattlesnake Ridge sandstone, or tuff), tracers, and groundwaters were used to measure radionuclide distributions between solid and liquid phases. Triplicate measurements were made for each combination of temperature, redox condition, tracer concentration, tracer type, groundwater composition, and interbed sample. Constant temperatures were maintained by placing the... 

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