Wells pumping

Total production from a well is the basis for calculating the ppm of chemical to be added treatment should not be based upon oil production alone. The initial treatment should be several times greater in concentration than subsequent periodic treatment. The batch is pumped into the annulus it must be followed by flush, generally with well fluids from the flow line. 

The amount of flush should be 158.9 to 145.2 liters, depending on the height of annulus fluid above the pump 159 liters (one barrel) of flush is adequate if the well pumps off daily, 795 liters (flve barrels) is generally adequate for 30.45 m of fluid above the pump, and 175.2 liters is adequate up to 152.4m of fluid above the pump. 

The height of fluid in the annulus can be determined by instruments such as the echometer. A water-soluble dye added to the flush water can be used to determine how quickly the treatment chemical reaches the bottom of the well. 

Reda pumps have been treated with weighted inhibitors. The bottom portion of the Reda is generally in water. Since the impeller of the Reda is in the top section, the bottom is not protected by inhibitor treatments through the annulus. Weighted inhibitors that fall to the bottom of the rat hole will protect the pump. 

Long or extended period batch treatments are occasionally performed on wells producing low water cut fluids (0 to 25% water). Oil-soluble or nearly oil-soluble inhibitors may be batched into the annulus. Usually half to one drum of chemical is used. The well fluids are circulated for two to four hours to mix the inhibitor into the annulus oil. The wells are then produced for a period of time (one month), when 37.8 to 56.7 liters (10 to 15 gallons) are again batched and the well circulated for two to four hours. With high fluid level wells this treatment has lasted for up to three months per batch. This procedure is a general guideline and the exact procedure should be supplied by tbe manufacturer. 

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Provide remote Stop buttons for circulation pumps well away from the furnace. 

Kurbel-pumpe,/. reciprocating pump, -welle, /. crankshaft. 

They have a characteristic smooth texture, thermal stability, good water resistance and are relatively inexpensive. The softer grades are easily applied, pump well and give low starting torque. Their application is limited by their relatively low drop points, which are around 100°C (212°F). This means that, in practice, the highest operating temperature is about 50°C (122°F). 

Figure 10-14. Inset Phololumincsccncc spectrum for low excitation pulse energy EP Main part (a) displays the spectrum for pump pulse energies well below the lasing threshold while (b) shows the spectrum obtained lor excitation with a pump energy close to the lasing threshold (c) presents the single mode-lasing spectrum emitted when the device is pumped well above threshold. The dashed lines indicate the zero line which is arbitrarily shifted in case of (b) and (c).

The common method of treating rod-pumped wells is to periodically batch inhibitor into them. The treatment period for a given well is selected using empirical rules based on well production volumes. A successful and economic corrosion inhibition program must carefully control the inhibitor concentration in the well fluids. Environmental aspects and efficacious inhibitor usage necessitate the measurement of very low corrosion inhibitor concentrations. Inhibitor concentrations as low as one part per million are significant, thus... 

The latter five bullets are obtained by using different forms of pumping tests. Such a test is normally done with a pumping well and a number of observation wells or pipes placed at certain distances from the well and in different directions. The duration varies but is commonly 1-2 weeks. 

During the test the groundwater table is monitored and the drawdown cone around the pumping well is established. From these drawdown data the hydraulic properties of the aquifer can be analyzed as shown in Figure 37. 

The pumping well method is more suitable for a water table that is too deep for the trench method. Pumps draw water, forming a cone of depression in the water table to control the movement of floating gasoline. The gasoline is then pumped out. The pumps can be either single- or a dual-pump... 

Installation of the pumping well is more time consuming than digging a trench. There is a lag period between the start of pumping, the formation of the depression cone, and containment of the plume. This limits its use as a rapid containment measure. The water table depression must be kept constant otherwise, if the water table is allowed to fluctuate, gasoline droplets may adhere to soil particles and get trapped below the water table, especially when the depth of the cone of depression gets lower. 

The distance between the injection-pumping wells should be such that approximately six injection-pumping cycles can be completed within a six-month period. 

In some configurations, the vacuum used in MPE increases the effective drawdown of ground-water (i.e., the increase or lowering of the depth of the groundwater table) locally near the pumped well. This has the effect of increasing exposed soil in the saturated zone and the removal of volatile contaminants located above and below the original water table. 

A typical result of conventional pumping in low conductivity and transmissivity formations is increased, and sometimes rapid, drawdown with steep gradients, with corresponding low recovery rates. This condition limits the influence of the conventional pumping well. MPE overcomes this limiting factor with the application of a vacuum. The vacuum enhancement of MPE also can overcome the capillary forces that can trap contaminants within the capillary zone. This allows better recovery of LNAPL, which tends to accumulate in the capillary zone at the air-water interface. 

FIGURE 3.20 Trace of half a cone of depression showing variations in drawdown with distances from a pumping well. 

Certain factors must, however, be considered in choosing the appropriate analytical solution unconsolidated vs. consolidated conditions, fully vs. partially penetrating wells, variable discharge rules, delayed yield, and aquifer boundaries. Most methods are best suited for unconsolidated aquifers with well-defined overlying and underlying boundaries, whereas with consolidated aquifers, the effective aquifer thickness is uncertain. A pumping well that fully penetrates a confined aquifer (i.e.,... 

Important to any aquifer restoration program is the radius of influence or capture zone to be anticipated during pumping. The radius of influence (rQ) for a vertical pumping well can be calculated using the following equation. 

Confined Steady state Huisman correction I and II Calculation Partially penetrating pumping well... 

Confined, matrix is Pumping well penetrates Curve fitting 1 Analysis for pumping well Gringarten and... 

Boulton, N. S. and Streltsova, T. D., 1977, Unsteady How to a Pumped Well in a Fissured Water-bearing Formation Journal of Hydrology, Vol. 35, pp. 257-269. 

Grubb, S., 1993, Analytical Model for Estimation of Steady-State Capture Zones of Pumping Wells in Confined and Unconfined Aquifers Ground Water, Vol. 31, No. 1, pp. 27-32. 

Mixed flow of water and LNAPL to a recovery well at a restoration site is very similar to oil and water flow to a pumping well in a low-pressure water drive reservoir. The equation used by Muskat (1936) to describe flow to a production well is presented below ... 

The second option considered was use of interception wells. One- or two-pump wells could be constructed at calculated spacings to create a hydraulic trough parallel to the canal to intercept the product. This design was considered more acceptable to the safety officer and the facility engineer, but was rejected by the maintenance foreperson because of the relative complexity of the operation system. The number of submersible pumps and sophisticated electronic controls would have required employment (or training) of technical specialists beyond the cost budgeted under normal operations. 

You wonder how much the weekly variation of trichloroethene, another pollutant, would be reduced from the river to the well. Use the following information on the aquifer porosity <(> = 0.37, solid phase density ps = 2.5 g cm"3, organic matter content of solid phase/. = 0.01 kg,. kg 1. Compare this attenuation with the case of a concentration variation at the well that is caused by a short pollution pulse of trichloroethene in the river. To what fraction is the maximum concentration reduced from the river to the pumping well Assume At = 1 hour for pulse duration. 

To 20 gms. (1 mol.) of iso-nitroso-camphor (see p. 307) dissolved in 35 c.ca. of glacial acetic acid, 9 gms. (excess) of sodium nitrite in 20 c.cs. of water are slowly added with mechanical stirring. Initially the temperature must not be allowed to rise above 20°, but when the evolution of gas ceases, the mixture is heated until no more gas is evolved. When cool, the whole is poured into an excess of cold water, and the precipitate filtered off at the pump, well washed with cold water, and dried on a porous plate. It is then sublimed at 60° (see p. 31). 

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