SC168P DHD350 Symmetric overburden casing drilling systems 168 Casing while drilling

Product Overview

Description

 

Concentric-Symmetric overburden casing drilling systems

SC168P-DHD350 Permanent/Non-Retrievable

 

 

 

 

About casing systems

Casing sistem (Casing while drilling) has been around for many years and it is one of proven technologiesthat can save both time and money. 

Casing system is a process where a well is simultaneously drilled andcased;  the casing is used for the drill string, and is rotated to the drill and cemented into the well at TD. 

One of the main benefits of this process is that it greatly cuts down on the tripping time neededto pull out the bottom hole assembly (BHA) and run the case- if not removing this need entirely.

Therefore, the flat time is reduced, and the process is made more economically viable.

 

Types of casing systems

Three main types of Casing system:

1. Eccentric casing system

2. Concentric casing ststem

    a. Concentric symmetirc casing system (Permanent/Non-Retrievable)

    b. Concentric symmetric casing system (Retrievable)

    c. Concentric casing system reamer type

    d. Concentric casing system slide bolcks type

    e. Concentric casing system wing type

3. Double drifiers casing system

 

The Symmetric casing system permanent type(non-retrievable)  is the simplest type. In this case, the system is made up of a drillable bit or drill shoe, a casing string, and a casing drive system.

The drill shoe is fitted securely to the bottom of the casing string; the latter is rotated by a power swivel which is hooked up to the drive system.

This system only offers a limited number of options- it can only drill in a straight hole, and to a pre-determined depth.

 

Symmetric is a system comprised of an ingeniously simple concentric method of drilling through overburden with casing.

Symmetric can drill straight holes at any angle (including horizontal) and to depths beyond 100 meters.

Working together as one efficient drill bit, the components are made up of:

• A pilot bit with large internal flushing holes and external flushing grooves.

• Symmetrical ring bit (reamer) with internal bayonet coupling

• Casing shoe for driving of casing.

• The pilot bit is attached to any common DTH hammer shank or top hammer rod thread.

The casing shoe is welded to the casing. The pilot bit and ring bit are locked together by the bayonet coupling.

They drill a hole large enough to allow the casing to be pulled into the hole.

The pilot bit and ring bit rotate with the drill string while the casing shoe and casing do not rotate.

When required depth is reached, the pilot bit is unlocked by a slight reverse rotation of the drill string.

The drill string and pilot bit will be retrieved through the casing, the ring bits and casing shoe will be left in the hole for permanent casing system.

Also the ring bits and casing can be retrievable through the special design for ring bits and casing shoe.

We can manufacture both permanent Symmetric and Retrievable Symmetric system which can meet your comprehensive requirement.

Features

• Complete types of drilling tools suitable for casing tubes with various diameters;

• Good stability and reliability granted by premium alloy steel material and fine CNC manufacturing process;

• Cost-effectiveness realized by mass production.

Applications

Water well drilling, geothermal well drilling, foundation piling, geological prospecting, etc.

 

 

 

Permanent/Non-Retrievable Concentric-Smmetric casing system technical parameter 

 

Casing tube data				Symmetric bits data
Nominal Dia.  (inch)	O.D.(mm)	I.D. (mm)	Wall thick -ness(mm)	Pilot bit Dia. (mm)	Reamer  Dia.(mm)	Max.O.D. of normal bit (mm)
4	114	101	6.5	99	126	75
5	140	120	10	118	154	96
6	168	148	10	153	188	125
8	219	198	10.5	196	243	170
10	273	247.6	12.7	245	298	203
12	325	299.6	12.7	294	350	255
14	355	329.6	12.7	326	380	285
16	406	380.6	12.7	378	438	340
18	460	431.6	12.7	426	468	390
20	508	482.6	12.7	478	538	445
22	560	534.6	12.7	521	580	495
24	610	581.6	14.2	574	630	514
26	660	631.6	14.2	618	680	590
28	711	682.6	14.2	674	731	606
30	762	730	16	724	782	669
32	813	781	16	769	835	709