Natural water drive

Natural water drive occurs when the underlying aquifer is both large (typically greater than ten times the oil volume) and the water is able to flow Into the oil column, i.e. it has a communication path and sufficient permeability. If these conditions are satisfied, then once production from the oil column creates a pressure drop the aquifer responds by expanding, and water moves into the oil column to replace the voidage created by production. Since the water compressibility is low, the volume of water must be large to make this process effective, hence the need for the large connected aquifer. 

The recovery factor (RF) is in the range 30-70%, depending on the strength of the natural aquifer, or the efficiency with which the injected water sweeps the oil. The high RF is an incentive for water injection into reservoirs which lack natural water drive. 

As reservoir pressure is reduced by oil production, additional recovery mechanisms may operate. One such mechanism is natural water drive. Water from an adjacent more highly pressured formation is forced into the oil-bearing formation by the pressure differential between the formations. Another mechanism is gas drive. Expansion of a gas cap above the oil as oil pressure declines can also drive additional oil to the wellbore. Produced gas may be reinjected to maintain gas cap pressure as is done on the Alaskan North Slope. Additional oil may also be produced by compaction of the reservoir rock as oil production reduces reservoir pressure. 

The number of injectors required may be estimated in a similar manner, but it is unlikely that the exploration and appraisal activities will have included injectivity tests, of say water injection into the water column of the reservoir. In this case, an estimate must be made of the injection potential, based on an assessment of reservoir quality in the water column, which may be reduced by the effects of compaction and diagenesis. Development plans based on water injection or natural aquifer drive often suffer from lack of data from the water bearing part of the reservoir, since appraisal activity to establish the reservoir properties in the water column is frequently overlooked. In the absence of any data, a range of assumptions of injectivity should be generated, to yield a range of number of wells required. If this range introduces large uncertainties into the development plan, then appraisal effort to reduce this uncertainty may be justified. 

Hydroelectric power is generated by flowing water driving a turbine connected to an electric generator. The two basic types of hydroelectric systems are those based on falling water and those based on natural river current, both of which rely on gravitation-... 

In primary recovery the natural energy comes mainly from gas and water in reservoir rocks. The gas may be dissolved in the oil or separated at the top of it in the form of a gas cap. Water, which is heavier than oil, collects below the petroleum. Depending on the source, the energy in the reservoir is called solution-gas drive, gas-cap drive, or water drive. In solution-gas drive, the gas expands and moves toward the opening, carrying some of the liquid with it. In gas-cap drive, gas is trapped in a cap above the oil as well as dissolved in it. As oil is produced from the reservoir, the gas cap expands and drives the oil toward the well. In water drive, water in a reservoir is held in place mainly by underground pressure. If the volume of water is sufficiently... 

The waler drive is generally the most efficient oil-production process. Oil fields in which water drive is effective are capable of yielding recoveries ranging up to 50% of the oil originally in place, it (1) the physical nature of the reservoir rock and of the oil are conducive to the process, (2) care is exercised in completing and producing llie wells, and (3) Ihe rale of withdrawal of products is optimal. 

Gelman, N., Machin, J. and Kestler, P. (1988). The nature of driving forces for passive water transport through arthropod cuticle../. Thermal Biol., 13,157-162. 

It is often loosely said that a catalyst "drives" a reaction. As the consideration here demonstrates, a picture more true to nature shows the reaction driving the catalyst. With its free-energy decrease, the reaction puts the catalyst system through its paces, much like water drives a water wheel. Rather than "driving" the reaction, the catalyst makes it possible by providing a pathway. 

If you live near a natural water source such as a stream or river, you could use the power from running water to drive a turbine or a water wheel to produce electricity. Depending on the flow rate of the water, microhydro sites can generate enough power for all the electrical appliances in a household. 

When oil is discovered in an underground reservoir, the initial stage of oil recovery occurs easily due to the inherent underground pressure acting on the field from associated water or gas. This forces oil to the surface via the bore at the production well. This process is known as primary recovery. In secondary recovery environments, additional force is applied to the reservoir to aid further oil recovery This is necessary when the natural pressure drive in the reservoir has either been depleted or was never sufficient from the beginning. The process usually involves water being pumped underground via an injection well. 

NESTOR, built at Winfrith, was based upon the JASON type of reactor (an American design) and constructed by the Hawker Siddeley Nuclear Power Company. It acted as a source of neutrons for the experimental assemblies of nuclear fuels and moderators used to obtain data for the design of reactor systems. JASON was modified to be capable of continuous operation at a power of up to 10 kW and its layout altered so that it could drive up to five experimental assemblies simultaneously. Natural water was used both as coolant and moderator. ... 

The expansion of the reservoir fluids, which is a function of their volume and compressibility, act as a source of drive energy which can act to support primary producf/on from the reservoir. Primary production means using the natural energy stored in the reservoir as a drive mechanism for production. Secondary recovery would imply adding some energy to the reservoir by injecting fluids such as water or gas, to help to support the reservoir pressure as production takes place. 

The material of interest is dissolved in a volatile solvent, spread on the surface and allowed to evaporate. As the sweep moves across, compressing the surface, the pressure is measured providing t versus the area per molecule, a. Care must be taken to ensure complete evaporation [1] and the film structure may depend on the nature of the spreading solvent [78]. When the trough area is used to calculate a, one must account for the area due to the meniscus [79]. Barnes and Sharp [80] have introduced a remotely operated barrier drive mechanism for cleaning the water surface while maintaining a closed environment. 

Generai description. Galvanic corrosion refers to the preferential corrosion of the more reactive member of a two-metal pair when the metals are in electrical contact in the presence of a conductive fluid (see Chap. 16, Galvanic Corrosion ). The corrosion potential difference, the magnitude of which depends on the metal-pair combination and the nature of the fluid, drives a corrosion reaction that simultaneously causes the less-noble pair member to corrode and the more-noble pair member to become even more noble. The galvanic series for various metals in sea water is shown in Chap. 16, Table 16.1. Galvanic potentials may vary with temperature, time, flow velocity, and composition of the fluid. 

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