Page 165 - Handbook Of Multiphase Flow Assurance

Paraffin wax 161

FIG. 5.32 Wax deposit thickness profiles in wells and in surface gathering lines (updated from Mazepa, 1965).
Distances are shown in meters.

TABLE 5.6 Production operating parameters for the waxy wells
Well parameters Gathering lines parameters
P_buffer D Deposit
Field Well Q (ton/d) (atm) L (m) (in.) P (atm) Burial (m) length (m)
Zaj-Karatayskaya 4028 75 17 600 2.5 17 0 400
Aznakayevskaya 4138 15 80 500 2.5 80 0 300
Aznakayevskaya 4136 26 79 500 2.5 79 0 350
Pavlovskaya 3901 32 4 400 4 4.0/5.0 0 75/100

The calculated critical flow rate of 70 tons/day was close to the observed value of 60 tons/
day.

Effect of PVT conditions
Temperature has the largest effect on the solubility of n-paraffin molecules in oil. When
temperature decreases, the molecules move slower and at some temperature may align to-
gether and form a solid crystal of wax. The heavier molecules with longer carbon chains