10  September  2010

The pre-existence of Tianhe Oil Group Co., Ltd is Mudanjiang Petroleum Machinery Co., Ltd, established in 1973. Tianhe Petroleum Machinery Joint-Stock Co., Ltd has restructured twice during the developing of the years. It has been organized as a Joint-stock company according to the Corporation Law in 2006.

The main products of Tianhe are drill collars, spiral drill collars, integral heavy weight drill pipe, and several kinds of drilling tools, work-over tools, cementing tools, coring tools, fishing tools and fitting, Hydraulic Bucking Unit, Hydraulic Jar Tester, Hydraulic Down hole Motor Tester, BOP automatic cleaning systems and other equipments which are including more than 120 types of products and more than 1000 Specifications.

Kelly Cock Valve

The kelly cock valve ,which is a manually operated ball valve run in the I.D of drill string ,is one of effective tool for preventation from blowout .The kelly cock  is divided into upper kelly cock valve and lower kelly cock . The upper kelly cock is connected between lower end of swivel and upper end of kelly. The lower kelly cock  is connected between upper end of drillpipe and lower end of kelly or connected between lower end of kelly saver subs. The kelly cock features a simple operation, the kelly cock  can be opened on or closed off by only turning the special operating spanner at 90 degrees according to indicating direction.During drilling operation,in order to avoid serious well kick or blowout accident, the kelly cock  shall be connected at upper end and lower end of kelly.

Table 1. Upper Kelly Cock

Type	O.D. (mm)	Thread connection (LH)	I.D. (mm)	Max.sealing pressure(Mpa)
CS 146	146	4 1/2 REG	50	68.6
CS 200	200	6 5/8 REG	76.2	68.6

Table 2 Lower Kelly Cock

Type	O.D. (mm)	Thread connection	I.D. (mm)	Max.sealing pressure(Mpa)
XS105	105	NC31	41.3	68.6
XS121	121	NC38	50	68.6
XS127	127	NC38	50	68.6
XS165	165	NC46	61	68.6
XS178	178	NC50 , 5 1/2FH	71.4	68.6