Orkiszewski Correlation

Orkiszewski Correlation Correlation Application

 This correlation correlation is utilizes the work work of Grith and Wallis Wallis for bubble ow and Duns and Ros for both transition and Annular Mist !n order for this correlation correlation to be accurate the pressure pressure drop infor"ation "ust also be accurate Orkiszewski de#eloped a correlation for the slu$ ow re$i"e% "akin$ the #alue considerabl& "ore accurate than the other correlations correlations This corr co rrelation elation is dee"ed satisfactor& for #ertical wells with a #ast ran$e of water'cut water'cut

This correlation is applicable for the following types of ow regimes: • • • •

(ubble )lu$  Transition  Transition Annular "ist

Method

Flow Regime

Grith Grith * Wallis Orkiszewski Duns * Ros Duns * Ros

(ubble )lu$ +densit& ter", )lu$ +friction ter", Transition Annular Mist

-i"itations

 This correlation% as with an&% ha#e li"itations within which the& pro#ide accurate results The Orkiszeweski correlation is li"ited to two'phase pressure drops across #ertical pipes

 The "ain li"itations to this "ethod of correlation are tubin$ size% Oil $ra#it& and Gas'-i.uid

 Tubin$ )ize -i"itation

 The tubin$ size of a production well is i"portant as it deter"ines the #olu"e of h&drocarbon bein$ produced alon$ with "an& other para"eters !n order for the correlation to produce accurate results the tubin$ size can onl& ran$e within one and two inches /or #alues recorded with a tubin$ size lar$er than two inches the Orkiszeweski correlation will produce an o#er esti"ate of the pressure loss

Oil Gra#it&

 The oil $ra#it& is a detri"ental factor in deter"inin$ the #alue of the h&drocarbons% the oil $ra#it& is t&picall& "easured in A0! de$rees The lower the A0! $ra#it& of an oil% ie the hea#ier the oil% the $reater the o#er'prediction in the correlation The ran$e in which the o#er' prediction occurs between thirteen and thirt& A0! !n order to ensure accurac& with this correlation% it should onl& be applied to oils with an A0! $ra#it& of thirt& and $reater The hi$her the A0! $ra#it&% the $reater the accurac& of the correlation

Gas'-i.uid Ratio +G-R,

 The $as'li.uid ratio of a reser#oir is representati#e of the total a"ount of $as in the reser#oir as a ratio to the total a"ount of li.uid in the reser#oir% ie oil and water This correlation holds accurac& up to a $as' li.uid ratio of up to 1222 after which the errors increase to o#er twent& percent

Conclusion

3o sin$le correlation can be applied to all t&pes of ow re$i"es and be considered to be "ost accurate% as such di4erent correlations are applied to di4erent ow re$i"es accordin$ to the resultin$ lowest "ar$in of error The Orkiszewski correlation is pro#en to be the "ost accurate when e5a"inin$ the slu$ ow re$i"es !t is well suited for #ertical wells with a lar$e ran$e of water'cut% howe#er the li"itations "ust be adhered to in order to pro#ide the "ost accurate results