Abstract: A method of measuring the oil content in the gross oil production of an oil well in which the percentage of solids content thereof is known, comprises the steps of introducing a predetermined weight of well production into said vessel, determining the time interval required to introduce said predetermined weight of well production into said vessel, determining the total well production flow rate of said well production into said vessel during said time interval, electromagnetically determining the percentage water content in said well production, determining from said percentage water content the water flow rate into said vessel during said time interval, determining from said known percentage solids content the solids flow rate into said vessel during said time interval, and determining the percentage oil content in said well production by deducting said solids flow rate and said water flow rate from said total well production flow rate.

Abstract: The pump jack is of conventional API front-mounted geometry Class III configuration, but is provided with an angularly disposed walking beam, so as to be able to pump a slant rod string. To incorporate versatility into the unit so that a single model can be used with different wells having different angularities, there is provided: means for altering the effective length of the Pitman arms (so that the angularity of the walking beam is changed, which permits the unit to be used with a rod string having a different slant); means for bringing the counterweight into phase with the well load; and means for altering the stroke length.