# US 5,704,427 A · Portable well service rig > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,704,427 A - Document ID: US5704427A - Status: Granted - Kind: A - Application number: 08/542,779 - Filed: 1995-10-13 - Granted: 1998-01-06 - Earliest claimed: 1995-10-13 - Inventors: David A. Buck; Daniel S. Bangert; Philip J. O'Connor - Web page: https://patentgrep.com/patent/US5704427A ## CPC - E21B 15/02: specially adapted for underwater drilling (E21B15/04 takes precedence) - E21B 19/002: {specially adapted for underwater drilling (E21B19/09, E21B19/143 take precedence)} - E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS ## Abstract The present invention provides a device for removing well casing from plugged and abandoned oil wells. The invention includes a unitary platform structure sufficiently small that the structure may be transported by boat to offshore well platforms and be lifted onto the well platform as a single unit. The platform also has a center station with an opening allowing the casing to pass therethrough. The device further includes at least one lifting means, which lifts the well casing through the center station. The present invention will serve many of the purposes of much larger drilling rigs or work over rigs typically employed on oil and gas well platforms. The present invention will be much quicker to transport and requires considerably less set-up time than dig rigs or work over rigs. ## Claims ### Claim 1 A self-contained well service rig comprising: (a) a unitary, crane liftable working platform; (b) a center station integral with said working platform, said center station having a center opening therein; and (c) a primary lifting device and a secondary lifting device attached to said working platform, wherein said primary and secondary lifting device are controlled by a central control station. ### Claim 2 (depends on 1) A well service rig as in claim 1, wherein said central control station is positioned on said working platform. ### Claim 3 (depends on 1) A well service rig as in claim 1, wherein said working platform is not substantially larger than necessary to accommodate an elevating floor with a rotary table, a control station and a derrick tower for stacking tubular members. ### Claim 4 (depends on 1) A well service rig as in claim 1, wherein said primary lifting device comprises at least one winch positioned in an inner equipment housing. ### Claim 5 (depends on 4) A well service rig as in claim 4, wherein said primary lifting device has two opposed winches and each of said winches are operably connected to a sheave assembly. ### Claim 6 (depends on 1) A well service rig as in claim 1, wherein said secondary lifting device is positioned adjacent to said center station. ### Claim 7 (depends on 1) A well service rig as in claim 1, wherein said secondary lifting device comprises a plurality of linear actuators. ### Claim 8 (depends on 1) A well service rig as in claim 1, wherein an elevating floor is connected said secondary lifting device. ### Claim 9 (depends on 8) A well service rig as in claim 8, wherein said center station has a recessed area surrounding said elevating floor, said secondary lifting device is positioned in said recessed area, and said elevating floor is sized to fit within said recessed area. ### Claim 10 (depends on 8) A well service rig as in claim 8 wherein a rotary table is positioned in said elevating floor. ### Claim 11 (depends on 10) A well service rig as in claim 10 wherein said rotary table has a center opening formed therethrough which is capable of accommodating oil field tools. ### Claim 12 A process for extracting well casing with a movable platform having a first and second lifting device contained thereon and said second lifting device having a rotary means attached thereto, said process comprising the steps of: (a) attaching said first lifting device to a first point on a tubular member; (b) applying an upward force to said tubular member with with said first lifting device; (c) attaching a cutting device to said rotary means and positioning said cutting device within said tubular member below said first point; (d) cutting said tubular member below said first point. ### Claim 13 A self-contained well service rig comprising: (a) a unitary, crane liftable working platform; (b) a center station integral with said working platform, said center station having a center opening therein; and (c) a lifting device comprising a linear actuator, said linear actuator being positioned adjacent to said center station such that said linear actuator may impart an upward force to a tubular member positioned to extend through said center station. ### Claim 14 (depends on 13) A well service rig as in claim 13, wherein said lifting device comprises a plurality of linear actuators. ### Claim 15 (depends on 14) A well service rig as in claim 14, wherein one or said plurality of linear actuators is position on at least two sides of said center station. ### Claim 16 (depends on 10) A well service rig as in claims 10, wherein an elevating floor is connected to said linear actuator. ### Claim 17 (depends on 16) A well service rig as in claim 16, wherein a rotary table is positioned in said elevating floor.