US 9,810,212 B2
Fluid load line calculation and concavity test for downhole pump card
Victoria M. Pons, Katy, TX (US)
Assigned to Weatherford Technology Holdings, LLC, Houston, TX (US)
Filed by Victoria M. Pons, Katy, TX (US)
Filed on Oct. 29, 2012, as Appl. No. 13/663,161.
Claims priority of provisional application 61/552,812, filed on Oct. 28, 2011.
Claims priority of provisional application 61/598,438, filed on Feb. 14, 2012.
Claims priority of provisional application 61/605,325, filed on Mar. 1, 2012.
Claims priority of provisional application 61/706,489, filed on Sep. 27, 2012.
Prior Publication US 2013/0108472 A1, May 2, 2013
This patent is subject to a terminal disclaimer.
Int. Cl. F04B 49/06 (2006.01); E21B 43/12 (2006.01); F04B 47/02 (2006.01); F04B 49/20 (2006.01); F04B 51/00 (2006.01); E21B 47/00 (2012.01); G05B 13/04 (2006.01)
CPC F04B 49/065 (2013.01) [E21B 43/127 (2013.01); E21B 47/0008 (2013.01); F04B 47/022 (2013.01); F04B 49/20 (2013.01); F04B 51/00 (2013.01); E21B 2043/125 (2013.01); F04B 2201/121 (2013.01); F04B 2201/1211 (2013.01); G05B 13/042 (2013.01)] 29 Claims
OG exemplary drawing
 
1. A method implemented by a processing device of diagnosing a pump apparatus having a downhole pump disposed in a wellbore and having a motor at a surface of the wellbore, the downhole pump reciprocated in the wellbore by a rod string operatively moved by the motor, the method comprising:
generating downhole pump data having values indicative of downhole load and downhole position of the downhole pump by using surface measurements and a wave equation model having damping;
determining, in a first determination, a first set of actual fluid load lines for actual fluid loads of each of an upstroke and a downstroke of the downhole pump from the values of the downhole pump data, the actual fluid load lines being additional to the values of the downhole pump data;
determining, in a second determination different from the first determination, a second set of calculated fluid load lines for calculated fluid loads of each of the upstroke and the downstroke of the downhole pump from load the values of the downhole pump data, the calculated fluid load lines being additional to the values of the downhole pump data and to the actual fluid load lines;
assessing damping used to generate the downhole pump data by comparing the first set of actual fluid load lines to the second set of calculated fluid load lines; and
modifying at least one parameter of the pump apparatus based on the comparison.