Parameter Optimization for Chemical Paraffin Control Jobs in Waxing Production Wells

The production wells at the 1st Henan oil production factory are characterized by high wax conten,25—45%,and very high watercut,85%.To control wax precipitation,an aliphatic amine initiated diblock copolyether,AE0604,as wax remover/inhibitor(WRI) is introduced into waxing wells through annulus in amount of 15.0—61.7 kg every 9.6—31.5 days.With submergence(S),volume of fluids produced(VFP),and WRI dosage taken as variables in approximately 100 well-time WRI introducing trials,the WRI production curves are constructed,the lasting time of effective working concentration of WRI(EWC),20—200 mg/kg,is determined and following results of trials are obtained: the peak of WRI production is sharp and appears in 50—20 hrs after WRI injected;the EWC maintains for 3—8 days and is influenced notably by S and less notably by VFP;the EWC lasting time can not be prolonged by the way of increasing WRI dosages;the downhole retention time of WRI is strongly influenced by water flush.A specification of downhole applying WRI is established: dosage 4—15 kg per well-time;interval between successive 2 injections 1—7 days;flow rate of flushing water20 L/min and flushing time 5 min.An optimized WRI injecting specification is formulated,covering dosages and intervals between 2 injections at different S and VFP values.As a result of putting this optimized specification into practice on more than 400 production wells,an increase in pump reconditioning intervals(from 197 to 271 day),in hot water well washing intervals(from 44 to 54 days),and in pump efficiency(from 44.9% to 50.1%) are observed.