Patent GB-771525-A (GB)
Title: A tool for use in wells
IPC: E21B49/10
Filed: 1955-10-18
Abstract: 771,525. Boring earth and rock. YANCEY, J. R., and ROBISHAW, S. [Representative of ROBISHAW, E. J.]. Oct. 18,1955 [Oct. 26, 1954], No. 29763/55. Class 85. A tool 18 for obtaining samples of well side wall formation fluids is connected by a sliding joint 16 to a drill string 12 and a sample container 20 is lowered down the drill string to seat in the tool 18 and receive the sample. A shoulder 164 on the container 20 engages a seat 162 in a piston member 100 which is slidable inside the casing 98 of the tool. The piston 100 is urged into an upper position by a spring 124 so that heads 226 on slips 224 attached to the piston 100 engage a tapered shoulder 230. A collar 116, slidable on the outside of the casing 98 is attached to the piston 100 by screws 118 passing through slots 122 in the casing 98. Linkages 132, 134 are pivoted at their upper end to the collar 116 and at their lower ends to a guide head 80. Each linkage has a nozzle 146 which is connected by a flexible tube 154 to a port 158 in the piston 100 which in turn communicates with a passage 176 in the container 20. The container 20 blocks the bore of the drill string so that fluid pumped down the string passes into the borehole through a nozzle 32 (Fig. 2A) but the pressure depresses the piston 100 which operates the linkages 132, 134 through the collar 116 and embeds the nozzles 146 in the wall formation. A clockwork mechanism in the container 20 lowers a plunger 200 (Fig. 2B) until it depresses a spring-loaded valve 204 so that ports 194, 192 register, when sample fluid passes from a nozzle 146, up the passage 176, past a check valve 180, through the ports 192, 194, through ports 206, 208 and into the sample container reservoir. The clockwork depresses the plunger 200 further to seal the sample in the container. The pressure in the drill string is reduced when the spring 210 moves the piston upwards retracting the linkages 132, 134 when the container 20 is withdrawn on a wire. If the linkages do not retract the container 20 is drawn upwards until a shoulder 236 engages shoulders 232 on the slips 224 when the piston 100 is pulled upwards. The nozzles may be at different levels and ports communicating with the passage 176 so arranged that only one nozzle is placed in communication with the sample chamber. The joint 16 comprises a lower inner member 58, 44 having a piston 46 axially slidable and rotatable in an upper outer member 26, 36 in which is mounted the nozzle 32. Bearings 66, 68 are mounted on each side of the piston 46 the space above which communicates with the borehole fluid through a port 56 and the space below which communicates with the drill string fluid through a port 60, so that as the pressure in the drill string increases the piston 46 is urged upwards to compensate for any stretch in the drill string 12. Splines 62 on the inner member 44 are prevented from engaging splines 64 at the bottom of the outer member 36 by two sleeves 74, 76 held axially spaced by shear pins 78. If the tool 18 gets stuck the drill string is pulled upwards until the pins 78 shear and the splines 62, 64 engage, when rotating the drill string will rotate the tool and clear it. Specification 771,526 is referred to.