API RP 11L:2008 pdf download
API RP 11L:2008 pdf download.Design Calculations for SuckerRod Pumping Systems (Conventional Units).
2.2The designer must realize that there are a number of unusual conditions which may be present in a well thatcould cause misleading conclusions from these design calculations. Some of these unusual conditions are:
a) slanted or crooked holes;
b) very viscous fluid;
c) excessive sand production;
d) excessive gas production through the pump; and
e) well flowing-off.
2.3 The research work was limited to simulated problems in which the tubing was assumed as being anchored atthe pump. Therefore, the test results reflected only this condition. However, because of the many known cases inwhich tubing is unanchored, a formula is included which, experience indicates, will give a very close approximation ofrelative plunger travel with respect to the pump. This value is identified with the symbol S$。.Examination of the formulawill reveal that the contraction of the tubing caused by the transfer of the fluid load from the standing valve to thetraveling valve is subtracted from the calculated plunger stroke. lt is realized that this formula is highly simplified andnot mathematically correct, but it is close enough for practical application.
2.4These design calculations may be used with confidence when applied to the broad category of average, normalpumping wells ftting the assumed conditions outlined in Annex A. Unusual, conditions not ftting the assumptions willcause deviations from calculated performance. The designer must recognize this fact even though he cannotcalculate quantitative values for this deviation.
3symbols and Formulas
3.1 Symbols, with Units Where Applicable, Used in the Technical Report
4.6 Perform the indicated mathematical operations indicated ifrough step 11 (per example Data Sheet ilL). If the tubing is anchored, Iik (step 11) Is equal to zero and need not be calculated, The values are now available with which the bottom hole pump stroke, S,,, and the pump displacement. PD. may be calculated.
4.7 With the calculated values of F,, 1St, aid MN,,, record the value of S1,IS from figure 4.1 and solve for S41, and PD In steps 13 and 14 (per example Data Sheet ilL) Pump displacement is the first test being made to see if the prelininary selection & components for the installation is satisfactory. If the purop displacement calcuLated in step 14 fails to satisfy known or anticipated requwements. appropriate adjustments must be made in the assumed data and steps I through 14 repeated. When the calculated pirp displacement is acceptable, proceed with the design calculations by performing steps 15.16 and 17.
4.8 By using the calculated values of F,,IS*, and MN,,, the values of Fi/SAr (see Figure 4.2). F’ ISA, (see Figure 4.3),
2T7S2&r (see Figure 4.4), and F3IS1, (see FIgure 4.5) are read from the curves and recorded. When refemng to Figures
4.1 and 4.6 to determine 5,/S and Ta, the value of NIN, must be used. Record the value Of Ta.
4.9 Substitution of the appropriate values in the various formulas and performance of the indicated mathematics Ii steps 23 through 27 of the example Data Sheet ilL will yield the various loads to be expected from the preliminary selection of equipment It Is now necessary to compare these calculated loads with limitations imposed by the preliminary selection. Calculate the stress in the sucker rods to determine if It is within acceptable limits.
410 Generally, more than one selection of equipment and calculation of operating conditions Is necessary before the optimum selection can be made.
