Patent ID: 6749019
Filing Date: 2004-06-15
Classification: E21B

Abstract:
An automatic paraffin removal unit comprising a scraper gripped on a pumping rod and upper and lower commutators connected to both ends of a tubing segment from a well head to a section having a temperature lower than a paraffin deposition temperature which requires paraffin removal,wherein the scraper comprises: a scraper body, a tumbler, an arc spring leaf, and a return torque spring, wherein three sheets of the arc spring leaves are mounted on both upper and lower ends of the scraper body such that their relative positions are staggered for 60 degrees over three rows of staggered rectangular through-holes, and wherein I-shaped notches are opened on a circle of the scraper body, and wherein screw cutting edges having positions staggered 60 degrees are mounted on both the upper and lower ends in which staggered round pits are mounted on both sides of the I-shaped notches, and wherein inward slotted grooves are opened at the upper and lower sections of I-shaped notches, and wherein the tumbler is mounted at the middle of the I-shaped notches, and wherein return torque springs are symmetrically mounted in the grooves on the upper and lower sections of the I-shaped notches, and wherein tooth-tips of short gear teeth on both sides of the tumbler are arc-shaped, whose arc radius is approximate to the tubing radius, and the tooth end of a middle tooth is rounded; and wherein the upper and lower commutators comprise a sleeve, an open spacing ring, and a tower spring, wherein an open spacing ring of the upper commutator is mounted in a cone cannelure on the upper section of the sleeve, and wherein the tower spring is inverted in the cone cannelure on the lower section of the sleeve, and wherein the open spacing ring of the lower commutator is mounted in the inverted cone cannelure on the lower section of sleeve, and wherein the tower spring is mounted in the cone cannelure on the upper section of the sleeve.