Steven V. Belden - Massillon OH Dennis D. Belden - Akron OH John G. Corp - Norton OH
Assignee:
Belden & Blake Corporation - North Canton OH
International Classification:
E21B 4325 F04B 4712
US Classification:
1661773
Abstract:
A swab is movably mounted within a well casing and automatically removes fluid from the well upon accumulated pressure at the bottom of the casing reaching a predetermined amount to raise the swab within the casing. The swab has a hollow body with an inner cylindrical bore. A control rod is slidably mounted within the bore and has a cross-sectional configuration whereby only a plurality of sliding contact lines occur between the rod and bore wall to reduce rod hangup and provide increased flow area between the rod and bore wall. A fluid inlet port is formed by an open bottom end of the swab body and is open and closed by a valve member located external of the swab body. The valve member has a generally pointed nose to reduce drag when the swab is descending into the casing, and upon contact of the nose with a stop at the bottom of the well casing, will automatically move to a closed position with the fluid inlet port. A pressure relief valve is mounted in the swab body and automatically opens upon the internal fluid lift pressure in the well casing reaching a predetermined amount to permit the pressure to equalize through the bore to prevent damage to elastomeric seals which surround the swab body.