Drilling process of large-diameter geological drilled hole

Abstract

The invention discloses a drilling process of a large-diameter geological drilled hole and relates to the technical field of drilling processes. A multi-segment connecting type combined drill rod is adopted as a drill rod. A torque transmission drill rod is mounted at the bottommost end of the combined drill rod. A small drill bit is mounted at the bottom of the torque transmission drill rod, wherein the small drill bit is used for drilling a core. A large drill bit is mounted on the lower portion of the torque transmission drill rod in a sleeving manner, wherein the large drill bit is used for drilling or coring. The large drill bit is connected with the torque transmission drill rod through a torque transmission mechanism. After primary residue collection or coring is completed through the large drill bit, the combined drill rod is reserved in the hole all the time, and the large drill bit is only lifted out of the hole. After residue is unloaded or a rock core is picked out, the large drill bit is dropped to the bottom of the hole along the combined drill rod once again. Synchronous rotation of the combined drill rod and the large drill bit is achieved through the torque transmission mechanism, and secondary drilling is conducted. By means of the drilling process, the drilling efficiency is greatly improved.

Description

technical field [0001] The invention relates to the technical field of drilling technology, in particular to a drilling technology for large-caliber geological drilling. Background technique [0002] With the development of modern industry, geological drilling is being used more and more widely. The diameter and depth of these drilling holes are varied due to different drilling purposes, and they are used in many fields, such as: exploration, petroleum, mining, etc. Water field, pile foundation field, mine field (wells for various purposes), sewage treatment field (aeration wells), etc. Generally speaking, the diameter of drilling wells used in fields such as exploration, oil and water production is relatively small, within a few hundred millimeters, while the diameter span of geological drilling used in fields such as pile foundations, mines, and sewage treatment is relatively large. The range varies from a few hundred millimeters to a few thousand millimeters, and the dia...

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Problems solved by technology

[0008] 1. But when drilling a deep hole, the weight of the drill pipe is very heavy. Every time the drill bit is lifted, the drill pipe must be completely lifted out of the hole, which consumes most of the lifting force of the drilling rig, so that it is really used to lift the drilling slag The lifting power is very limited;

[0009] 2. It is difficult to achieve effective flushing of the bottom of the hole. Many people in the industry have tried a variety of methods for flushing the bottom of the hole, such as gas lift reverse circulation, mechanical disturbance at the bottom of the hole, etc., but they are all unable to do so due to various limitations. To achieve the expected effect, the bottom of the hole is repeatedly broken, and the friction between the drill bit and the wall is very large, so that a large part of the drilling torque and pressure provided by the rotary drilling rig are consumed by the repeated breakage at the bottom of the hole and the drill bit and the hole. The friction between the walls seriously affects the efficiency of rotary drilling rigs in large-diameter hard rock drilling;

[0010] 3. Furthermore, limited by the telescopic rod, the absolute drilling depth is relatively small, and when the drilling depth is relatively deep, the drill rod to be used becomes very long, resulting in a smaller diameter of the inner drill rod of the telescopic rod. fragile

[0013] 1. The auxiliary drilling time required for disassembling and assembling the drilling tools is very long, which determines that the full-face reverse circulation drilling rig cannot frequently lift the drill;

[0014] 2. When the diameter of the drilled hole is large and the rock is hard, the drilling pressure and torque required for the full-section crushing of the entire bottom of the hole are very large. As far as the current full-section reverse circulation drilling rig is concerned, it is impossible to provide high-efficiency crushing at all. The required torque and WOB (including the weight of drill collars that can be used) make full-face reverse circulation drilling rigs very inefficient when drilling large-diameter hard rocks, and sometimes it is difficult to form effective footage

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