A new model for studying oilwell pumping installations

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SPE
A New Model for Studying Oilwell Pumping Installations by J.E. Chacin U., INTEVEP S.A., and J.C. Purcupile, U. of Oklahoma

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1SS7. Sooely

01 Pedleum

Engineers at the 62mi Annual Techmcal Conference and Exhmmon ot the Society ok Petroleum Engineers held m

TfIIs paper was prepared for pre.eentatmn Oallas. TX September 27-20. 19S7

Th,a pepef was selected for preaentalrm by an SPE Program Commtttea Iollowmg review of mlormatmn contained m an abalractsubmmadby the author(a)Contentaof the paper. aa preeented. have no! been rewewed by the BOCIOIY of Pelroteum Engmaars and are subjacl 10 corract!an by the a aufhor(s) Tha material, a presented.does not neceaaarJyreftactany t=tlon of the Scciety of PetroteumEm#nears,es officers.or members Papers

to COPY Ie praaanwdat SPE maetmgaare sub@ 10pubficafon reww by Editorial ommmeeeof Iha Somafyof PetroleumEngmaere Permiamon C may restricted to anebatrart more 300 01 nol than WWOS lBu61r0fZmS not be copd The ebafracIaIwfsf confamccmap+wws acknowfe8gmenlof Tetex. 7W48D SPEDAL where qnd by whom the paperISPfeaantao write Pubtcatona Manager.SPE, P O Box633636. RIcfwaaon,Tx 75003S36 ABSTRACT
A digital discrete model, similsr to the analog model investigated by Midwest Research, has been f developed to etudy pusapof, pumping with anchored tubing, and gas interference downhole conditions. The calculated surface dynagraphs are presented for unanchored tubing, anchored tubing, 60% gas interference, 20 gaa interference, and 80% pumpoff.

Gibba6*7). In the formulation of the solution, the damping coefficient In the wave equation is treated as an empirical constant which varys between 0.1 to 0.5 see-’. More recently, Doty and Scttmidt* hwve formulated a pumping model that includes the dynmics of the fluid motion and uses experimental correlation, obtained by Valeev snd Repin,g to establish the frictional damping forces between the rods and the fluid. In this inveetigstion, a discrete model for rod