Lifting actual expense of lifting oil varies greatly. The smaller the production of a well the greater the cost. With new wells of large production, say 50 to 100 bbls. each per day, the actual lifting cost plus overhead may be as low as 50 per barrel, or as high as 200. Ten cents is a fair average for wells of such a size. Wells making 1 bbl. may cost as high as $1.50 per barrel. No rule can be laid down for such costs.
However, on one Mid-Continent lease 200 wells are handled by five pumpers and one roustabout. These wells average M bbl. each or 3000 bbl. a month. The total cost of labor, lease expense and overhead is $1500 or 500 per barrel, a very low cost.
In California an average 2500-ft. property with 10 wells making 30 bbls. each per day would cost as follows: 300 bbl. per day, 9000 per month-30 days. Two pumpers, one well crew, three men, a teamster and two firemen made up the crew. The total cost would run (including superintendence, wear and tear and all overhead) $3000 per month, or roughly, 33M0 per barrel. This is by no means a high figure.
Capacity of speed of the pumps ranges from 10 strokes per minute for very heavy oil to as high as 20 strokes per minute for lighter oil. With the walking beam the second hole is used, which gives a 16-in. stroke although an 18-in. stroke is some times used.
For a 3-in. pump with a stroke of 16 in. the pumping capacity for 20 strokes per minute would be: 49 X 20X 1440 42 — 336 bbl. per day.
A 2-in. pump with a stroke of 16-in. would give, in the ratio of = 4 : 9 = 149.4 bbl. per day.
Where a pumping power is used the stroke is usually less and the number of strokes per minute is less.
A stroke of 12-in. and 15 strokes per minute will raise with a 2-in. pump .163 X15 X 58680 = 83. 828 bbl. per day.
42 = 7 A 3-in. pump will raise % of a 2-in. or 188.6 bbl. per day.
_ Pumps, however, seldom pump their full capacity. For some old wells the fluid is exhausted in an hour or two. The pumping is then stopped, the well unshackled and allowed to stand for several days until it has obtained more oil. Continued pumping does little or no good in such cases. Where a well makes enough oil to fill the casing, and responds steadily to pumping, continuous operation is necessary to obtain the oil.
Placing the Pump.—It is advisable in wells making little sand, to place the pump just above the top of the pay. Pumping the oil to a lower level than the pay sand may result in paraffining of the sands with oils of paraffine base.
In wells making much sand, or when the fluid stands high in the well, place the pump several hundred feet in the fluid.
For example, if a well is 3000 ft. deep and the fluid rises 1500 ft., place the pump at 2000 ft. As the fluid leverf ails after con tinued pumping, lower the tubing, always keeping the pump as high as possible.
Pumping near the bottom of the hole is practiced by some oil operators who desire to keep the sand moving, but the practice is a questionable one. Such wells experience great trouble with worn out pumps and with wells "off the beam" a large part of the time.