Continuous sands

Shallow marine/ coastal (clastic) Sand bars, tidal channels. Generally coarsening upwards. High subsidence rate results in stacked reservoirs. Reservoir distribution dependent on wave and tide action. Prolific producers as a result of clean and continuous sand bodies. Shale layers may cause vertical barriers to fluid flow. 

Shelf (elastics) Sheet-like sandbodies resulting from storms or transgression. Usually thin but very continuous sands, well sorted and coarse between marine clays. Very high productivity but high quality sands may act as thief zones during water or gas injection. Action of sediment burrowing organisms may impact on reservoir quality. 

This process, according to the manufacturer,54 has been developed in such a way that space requirements are kept to a minimum. A BIOPAQ IC reactor is used as the initial step in the treatment process. The name of this anaerobic reactor is derived from the gas-lift driven internal circulation that is generated within a tall, cylindrical vessel. These reactors have been operational in the paper industry since 1996. The second step in the purification process is a mechanically mixed and aerated tank. The aerating injectors can be cleaned in a simple way without the need to empty the aeration tank. Potential scaling materials are combined into removable fine particles. At the same time, the materials that may cause an odor nuisance are oxidized into odorless components. The process can be completed by a third and a fourth step. The third step focuses on suspended solids recovery and removal. The fourth step is an additional water-softening step with lamella separation and continuous sand filters in order to produce fresh water substitute. The benefits claimed by the manufacturer are as follows54 ... 

BioMeteq A biological process for removing trace metals from oil refinery effluents. The effluent is passed upward through a continuous sand filter. A biofilm of bacteria on the sand particles reduces and precipitates the metals. An air blast scours the precipitates from the sand, which is washed and returned to the process. Developed by Paques BV, the Netherlands, and piloted in Germany in 2005 for removing uranium and selenium. 

Figure 1.44 Schematic representation of a continuous sand filter where wash liquid is used to progressively clean the sand bed (left) and photograph, with permission from Sernagiotto, of a sand filter with automated backflush facility (right).

Kiln Car. A car for the support of ware in a tunnel kiln or bogie kiln the car has four wheels and runs on rails. In a tunnel kiln, through which a number of these cars are moved end-to-end, the metal undercarriages are protected from the hot kiln gases by continuous sand-seals. The car deck is constructed of refractory and heat-insulating material. 

As we pointed out in Chapter 3, in many elementary treatments, the dependence of P on 9 is not considered. But we showed that while the log r solution is useful in modeling flows in continuous sands where pressure does not jump, the 0 is ideal for modeling the effects of solid obstacles placed in the midst of larger scale flows that do support pressure differences. 

Whereas pressure is double-valued through a solid shale, the corresponding streamfunction, interestingly, is single-valued the shale segment is a streamline of the flow. This is also obvious because it is not a source (or sink) that creates (or destroys) fluid. Thus, numerical methods developed for pressure fields in continuous sands, or for steady-state temperature fields in heat transfer problems without embedded insulators, can be naively and directly used for shale flow... 

Cancun beaches is shown in Fig. 20.36(a), in which the raised limestone platform extends 200 m offshore and supports a relatively thin sand layer on top (1.0—1.5 m maximum thickness). This natural raised structure forces waves to break some distance offshore and results in an area with calm seawater and white sand beaches, making for ideal conditions for water sports and safe relaxation. A large frontal dune stmcture had existed at the rear of the beaches, but with the development of large seaside resorts since the mid-1970s, this frontal dune structure was destroyed and thus it cannot contribute sand to the beaches to compensate for sand loss resulting from littoral processes. Furthermore, waves from storm activity contribute to continual sand loss from the beaches. 

On a microscopic scale (the inset represents about 1 - 2mm ), even in parts of the reservoir which have been swept by water, some oil remains as residual oil. The surface tension at the oil-water interface is so high that as the water attempts to displace the oil out of the pore space through the small capillaries, the continuous phase of oil breaks up, leaving small droplets of oil (snapped off, or capillary trapped oil) in the pore space. Typical residual oil saturation (S ) is in the range 10-40 % of the pore space, and is higher in tighter sands, where the capillaries are smaller. 

If the original field development plan was not based on a 3-D seismic survey (which would be a commonly used tool for new fields nowadays), then it would now be normal practice to shoot a 3-D survey for development purposes. The survey would help to provide definition of the reservoir structure and continuity (faulting and the extension of reservoir sands), which is used to better locate the development wells. In some cases time-lapse 3-D seismic 4D surveys carried out a number of years apart, see Section 2) is used to track the displacement of fluids in the reservoir. 

Reservoir pressure is measured in selected wells using either permanent or nonpermanent bottom hole pressure gauges or wireline tools in new wells (RFT, MDT, see Section 5.3.5) to determine the profile of the pressure depletion in the reservoir. The pressures indicate the continuity of the reservoir, and the connectivity of sand layers and are used in material balance calculations and in the reservoir simulation model to confirm the volume of the fluids in the reservoir and the natural influx of water from the aquifer. The following example shows an RFT pressure plot from a development well in a field which has been producing for some time. 

Place 50 g. of o-chloronitrobenzene and 75 g. of clean dry sand in a 250 ml. flask equipped with a mechanical stirrer. Heat the mixture in an oil or fusible metal bath to 215-225° and add, during 40 minutes, 50 g. of copper bronze or, better, of activated copper bronze (Section 11,50, 4) (1), Maintain the temperature at 215-225° for a further 90 minutes and stir continuously. Pour the hot mixture into a Pyrex beaker containing 125 g. of sand and stir until small lumps are formed if the reaction mixture is allowed to cool in the flask, it will set to a hard mass, which can only be removed by breaking the flask. Break up the small lumps by powdering in a mortar, and boil them for 10 minutes with two 400 ml. 

Mix intimately in a mortar 100 g. of sodium laevulinate, 250 g. of phosphorus sulphide (1) and 50 g. of clean dry sand. Place the mixture in a flask fitted with a condenser for distillation and a receiver (2). Heat the flask with a free flame until the reaction commences, and then remove the flame. When the reaction subsides, continue the heating until distillation ceases. Wash the distillate with 10 per cent, sodium hydroxide solution to remove acidic by-products and steam distil. Separate the crude 2-methyltliiophene from the steam distillate, dry over anhydrous calcium sulphate, and distil from a little sodium. Collect the pure compound at 113° the yield is 30 g. 

Method B. Place 125 g. (106 -5 ml.) of diethyl phthalate and 25 g. of molecular sodium (sodium sand see Section 11,50,6) in a 500 ml. round-bottomed flask fitted with a reflux condenser and dropping funnel. Heat the flask on a steam bath and add a mixture of 122 5 g. (136 ml.) of dry ethyl acetate and 2 5 ml. of absolute ethanol over a period of 90 minutes. Continue the heating for 6 hours, cool and add 50 ml. of ether. Filter the sodium salt (VI) on a sintered glass funnel and wash it with the minimum volume of ether. Dissolve the sodium salt (96 g.) in 1400 ml. of hot water in a 3-htre beaker, cool the solution to 70°, stir vigorously and add 100 ml. of sulphuric acid (3 parts of concentrated acid to 1 part of... 

Alternative feedstocks for petrochemicals have been the subject of much research and study over the past several decades, but have not yet become economically attractive. Chemical producers are expected to continue to use fossil fuels for energy and feedstock needs for the next 75 years. The most promising sources which have received the most attention include coal, tar sands, oil shale, and biomass. Near-term advances ia coal-gasification technology offer the greatest potential to replace oil- and gas-based feedstocks ia selected appHcations (10) (see Feedstocks, coal chemicals). 

High purity 75% ferrosihcon containing low aluminum and calcium can be used in continuously cast heats where nozzle blockage is a problem. In iron melting, this ahoy is desirable to minimize buildup on refractory faces in the furnace or on stopper rods or nozzles. Low aluminum ferroshicons can also help reduce hydrogen pin holes in castings poured in green-sand molds. 

Because of the diversity of available information and the continuing attempts to delineate the various world oil sands deposits, it is virtually impossible to reflect the extent of the reserves in terms of barrel units with a great degree of accuracy. The potential reserves of hydrocarbon Hquids that occur in tar sand deposits have, however, variously been estimated on a world basis to be in excess of 477 x 10 (3 x 10 bbl). Reserves that have... 

---