Drill core extractor

Abstract

A system for extracting drill cores from a borehole. The system enables a semi-resilient sleeve-inserted in a housing—to be sealed about the circumference of a drill rod thereby allowing for upward backpressure against the drill core when activated. The system comprises: a housing assembly having sleeve retaining annular rings with edge treatment that forces outward displacement of the central region of the sleeve so as to ensure utmost clearance from a drill rod, which traverses said sleeve. The system thereby allows extraction of drill core samples without the time-consuming fishing method therefore increasing productivity by a substantial margin.

1 . A drill core extractor comprising:
 a. a seal assembly having:
 i. a male casing adapter comprising: a rigid tubular body threaded at a lower end to mate with a female casing, a forming end, water ports, an attachment flange about the full circumference of the tubular adapter wherein said flange further comprises a plurality of fastener perforations therethrough, 
 ii.—a grip ring having a plurality of fastener perforations therethrough and in direct alignment with those of the male casing adapter, and a plurality of grip slots arrayed about the grip ring's outer circumference for use to apply a wrench therein for rotable insertion and removal of the assembly on and off a female casing adapter, 
 iii.—a sleeve housing having a round tubular body with a lower flange having a plurality of fastener perforations therethrough in direct alignment with those of the male casing adapter and the grip ring, and an upper flange also having a plurality of fastener perforations therethrough in direct alignment with those of a retainer ring, a water inlet angularly and threadedly engaged above the base of the sleeve housing and in direct alignment with a first water port within the male casing adapter, a water outlet also angularly and threadedly engaged above the base of the sleeve housing distal from the inlet and also in direct alignment with a second water port within the male casing adapter, an outwardly raised continuous annular depression located centrally within the sleeve housing inner wall through which an oil inlet is adapted, 
 iv.—a retainer ring comprising a annular flanged body with a raised central diameter adapted to engage frictionally within an opening of the upper portion of the sleeve housing and said flanged body also having a plurality of fastener perforations therethrough in direct alignment with those of the upper flange of the sleeve housing, 
 v.—an upper oil seal frictionally retained within a seal slot at the upper inner portion of the sleeve housing, which said upper oil seal also engages frictionally against the outer circumference of the raised central portion of the retainer ring thus forming an impermeable seal therebetween, 
 vi.—a lower oil seal also frictionally retained within a seal slot at the lower inner portion of the sleeve housing, which said upper oil seal also engages frictionally against the outer circumference of the male casing adapter also forming an impermeable seal therebetween, 
 vii.—a sleeve fabricated of a semi-resilient rubber-like compound, which said sleeve having an outer diameter generally equal to that of the inner diameter of the sleeve housing and a length slightly greater than the distance between a form ring and the forming end at the uppermost portion of the male casing adapter, 
 viii.—a form ring having an annular body wherein its upper face is planar and its inner face is adapted with two circumferential peaks, 
 ix.—an oil inlet threadedly engaged through the sleeve housing wherein the oil inlet is in communication with the outwardly raised continuous annular depression located centrally within said sleeve housing, and fasteners securedly holding the assembly as one. 
   b. a method of extracting drill core samples comprising the steps of:
 i. de-energizing the drill to halt rotation, 
 ii. removing drill head from drill rod, 
 iii. pressurizing hydraulic sleeve seal about the periphery of the drill rod, 
 iv. activating water pump and directing high-pressure water into the water inlet, 
 V. allow core sample to attain a height sufficient enough to surface above drill rod, 
 vi. grasp core sample for retrieval from drill rod, 
 vii. re-assemble drill head, reconfigure water flows, de-pressurize sleeve seal and continue drilling. 
   
   
   
       2 . The drill core extractor of  claim 1  wherein the present seal assembly can be adapted with current water cooling hard rock drilling rig systems without the addition of specialized tools. 
   
   
       3 . The drill core extractor of  claim 1  wherein the direction of water-flow through the drill rod is reversed during the core extraction process. 
   
   
       4 . The drill core extractor of  claim 1  wherein the male casing adapter is further adapted with a forming end having two circumferential offset peaks oriented such that the peaks pressuredly contact with the circumferencial end surface of a tubular sleeve, wherein the central-most peak extends toward the sleeve more so than the outer peak, which said outer peak is rather slightly recessed thereby encouraging an outward central bulge tendency at the sleeve's circumference. 
   
   
       5 . The drill core extractor of  claim 1  wherein the retainer ring is further adapted with a forming end having two circumferential offset peaks oriented such that the peaks pressuredly contact with the circumferencial end surface of a tubular sleeve, wherein the central-most peak extends toward the sleeve more so than the outer peak, which said outer peak is rather slightly recessed thereby encouraging an outward central bulge tendency at the sleeve's circumference. 
   
   
       6 . The drill core extractor of  claim 5  wherein the forming end of the retainer ring is oriented in mirror image of the forming end of the male casing adapter. 
   
   
       7 . The drill core extractor of  claim 1  wherein the outwardly raised continuous annular depression located centrally within the sleeve housing inner wall enables a body circumferential communication of compressed fluid to exert equal for against the sleeve's outer wall so as to ensure the sleeve's inner wall mates evenly about the outer diameter of an immobilized drill rod.