WO2009132645A2 - Grappler - Google Patents

Abstract

The invention relates to the "catching and gripping or releasing of objects in a borehole by gripping from outside for example by overlapping" (E21B 31/18) with a grappler, by means of which a cable core barrel or another tool (for example a borehole measuring device), provided with a flange at the head end thereof, can be gripped in the bore string and removed from the bore string by means of a cable. After securing the cable core barrel or the tool against falling back into the bore string the grappler can be released from the flange by simply removing the load on the cable. Unlocking can thus be achieved in remote controlled operation without manual support from outside the bore string.

Description

 Description hook catcher

The invention relates to a hook catcher that can catch or grasp an object in a drill string and that can be released from the object outside the drill pipe by relieving the pull rope.

Technical area

E21 B 31/18 "Catching and gripping or loosening of objects in the borehole from the outside, e.g. across ".

State of the art

1. "Well tool placement and hositing implement" (Stokes, 1921)

It is known to loosen the connection between hook catcher and tool in a drill string by a cylindrical sleeve is passed over the rope and pressed by gravity on the upper end of the hook catcher so that it opens and releases the mandrel (US1, 442.188) ,

2. "Overshot" (Stokes, 1928)

It is also known to change the hook shape of the hook catcher to avoid snagging in a drill string (US1, 719,144).

3. "Overshot" (Sherman, 1936)

In order to prevent jamming of the tool when pulling in the drill string, it is also known to break a defined element in a spring element in the hook catcher, so that it is released and can be recovered without the tool (US2,128,102).

4. "Overshot" (Lang, 1938)

To protect against the tearing of the pull rope by overloading, due to a jammed tool, it is also known to achieve an automatic release of the hook catcher from the tool (US2,266,873).

5. "Dry hole wire core barrel apparatus" (Anderson / Svendsen, 1974)

It is also known to use two different hook catcher respectively for the insertion of a tool in a drill string and for catching or pulling (US3,930,679).

6. "Overshot" (Taylor, 1975)

For independently releasing the hook catcher of a tool or core tube in the drill string, it is known to modify the principle of the hook catcher so that the sleeve is now part of the hook catcher and is operated by spring force (US4,004,835). 7. "Releasing device in core barrel grapplers" (Eriksson / Egnelov, 1981)

For mechanically releasing the overshot of the inner core tube in the drill string, it is also known that once the overshot has reached its working position by a groove is incorporated in the drill string at a defined distance from the working position, the opening of a locking hook is allowed in the hook catcher. (US4431225)

8. "Cable Overshot Apparatus" (Abie, 1998)

For safe recovery of a tool or a core tube is also known to pull this on the hook catcher from the pipe and store horizontally. The hook catcher is manually removed by the drill master (US6,109,373).

9. "Lockable Overshot" (Beach, 2002)

In order to prevent uncontrolled opening when recovering the closure sleeve of the hook catcher, it is known to place the hook of the hook catcher in a protective sleeve, which can be locked by a closure sleeve (US2004 / 0195852A1).

10. "Overshot for Down Hole Drilling Operations" (Anderson, 2006)

In addition, it is known to provide hook catcher with a sprocket, with the aid of which the hooks in the drill string are opened by repeated pulling (WO2007 / 041778A1).

Basic technical problem / question

The specified in claim 1 invention is based on the problem of developing a way of unlocking the safety gear of objects, for example. Of cable core tubes, which can be performed in remote controlled operation without manual assistance outside of the drill string. All current commercial safety gear requires manual release by the drill guide. In the standard method of rope core drilling, the drill master secures the inner core tube from the drill string after pulling and then manually disconnects the hook catcher from the mandrel (e.g., by opening the snap hooks against the spring resistance by finger pressure).

IV. Solution

This problem is solved by the listed in claim 1 feature that the hook catcher can be solved by a simple strain relief on the rope solved.

V. Advantages of the invention

With this invention, the hook catcher can be released outside of a drill string without additional manipulation and does not need to be readjusted before next use. This is particularly important in remote-controlled drilling rigs, which are applied, for example, in the cable core drilling. VI. Figure bullet

The drawings illustrate an embodiment of the invention which is particularly suitable for wire-core drilling methods:

Fig. 1 is a three-dimensional drawing of the hook catcher. Fig. 2 is a partially sectioned side view of the hook catcher.

VII. Embodiment

In the invention, it is a hook catcher with which a Seilkern- inner tube or other tool (eg, a logging tool), which is equipped at its head end with a mandrel, can be grasped in the drill string and pulled with the aid of a rope from the drill string , After securing the Seilkern- inner tube or the tool against a relapse into the drill string, the hook catcher can be solved by simple strain relief on the rope from the mandrel.

Central component of the hook catcher (01) are two opposite snap hooks (02), which are centrally connected by a bolt (03) with a base body (04). The bolt is secured with a split pin (05). The snap hooks are pressed apart in this suspension in the upper part of the snap hook, by a spring (06), whereby the hooks (07) in the lower part of the snap hooks (02) are firmly opposed.

If the hook catcher (01) hits the mandrel (08) in the drill string when lowered, the snap hooks (02) are pressed apart by the weight of the hook catcher (01) against the spring force and slide over the mandrel (08). The geometry of the hooks (07) is adapted to the mandrel (08), which is flat or convex shaped at the bottom to ensure a secure gripping the snap hook (02). The snap hooks (02) are connected to the main body (04), which is tuned with its outer diameter and minimum length on the drill string so that it can slide up and down in the drill string and is centered by the drill string. This ensures that the snap hooks (02) are safely guided over the central mandrel (08) and after passing over the mandrel (08) in the drill string can not be detached from this. The hook catcher (01) is provided with a fastening possibility (09) for a rope with which the hook catcher (01) is guided up and down the drill string. The cylindrical base body (04) can be provided parallel to its longitudinal axis with generous grooves (10) to allow a speedy lowering of the hook catcher (01) on the rope in a water-filled drill string. By choice of material and length of the cylindrical base body (04), the weight when lowering can be optimized.

After catching the dome (08) by the hook catcher it is pulled out of the drill string on the rope. In the next step, the rope core inner tube or the tool pulled out of the drill string is secured against slipping off. This can be done for example by a gripping arm, which can also be used for the vertical parking of the tool in a rod magazine. Since the hook catcher (01) is designed to be open at the bottom of the snap hook, extends outside the drill string a simple strain relief on the rope, so that the hooks (07) from the mandrel (08) slip and the hook catcher (01) from Seilkern- inner tube or from the tool is released. This slipping at Zugentlasten can be additionally supported eg by an asymmetric weight distribution in the hook catcher (01). Furthermore, the base (11) of the cylindrical base body (04) can be concave or designed with an inclined plane, so that the base body (04) slips laterally after placing the base (1 1) on the mandrel (08).

Claims

VIII. Claims 1. hook catcher with which an object, which is equipped at its head end with a mandrel caught in a drill string or gripped and loosened, characterized in that the hook catcher in the drill string the mandrel safely attacks while he outside of the drill string by a simple Strain relief on the rope can be released from the mandrel. 2. hook catcher according to claim 1, characterized in that it consists of at least two snap hooks. 3. hook catcher according to claim 1, characterized in that it consists of two opposite snap hooks, which are connected by a bolt to the base body. 4. hook catcher according to one of the preceding claims, characterized in that the bolt is secured with a split pin. 5. hook catcher according to one of the preceding claims, characterized in that the two opposite snap hooks close by spring force. 6. hook catcher according to one of the preceding claims, characterized in that the base body is provided with at least one groove. 7. hook catcher according to one of the preceding claims, characterized in that the groove extends parallel to the longitudinal axis. 8. hook catcher according to one of the preceding claims, characterized in that the base body has an outer diameter, a minimum length and a minimum weight, so that it can slide up and down in the drill string and is centered in the drill string. 9. hook catcher according to one of the preceding claims, characterized in that at the head end of the base body, a holder is attached to which the hook catcher can be attached with a rope. 10. hook catcher according to one of the preceding claims, characterized in that the base of the base body forms an inclined plane. 1 1. hook catcher according to one of the preceding claims, characterized in that the snap hook, when lowered in the drill string on the mandrel, are pressed apart by the weight of the hook catcher against the spring force and push over the mandrel. 12. hook catcher according to one of the preceding claims, characterized in that the snap hooks are adapted to the geometry of the cathedral. 13. hook catcher according to one of the preceding claims, characterized in that the snap hooks are guided over the central mandrel and after passing over the dome in the drill string can not solve this. 14. hook catcher according to one of the preceding claims, characterized in that the hook catcher is designed to be open at the bottom of the snap hook so that the snap hooks outside the drill string slip from the mandrel as soon as the pull rope is relieved, whereby the hook catcher is released from the object.