ROTAR SUB AND OTHERS

Rotary subs are made from 4145H modified quenched and tempered material to API specifications, and carry the API monogram. They can be used to crossover from connection size to another or as the disposable component used to extend the connection life of a more expensive drill stem member.

Lift sub

A lift sub enables the safe, efficient handing of straight OD tubular such as drill collars, shock tools, jars, directional equipment and other tools by using the drill pipe elevators.

Lift plug

The lift plug is a small easy-to-handle sub that makes up in the top of the drill collar. It has a lifting flange that serves as a safety stop when drill collars without elevator recesses are being tripped out of the hole. The center section of the lift plug is bored out to reduce weight for easy handing.

Saver sub

Saver sub is used to extend the life of the Kelly by taking the connection wear each time it is make-up to a drill stem component. The saver sub connection is sacrificed because it can be easily repaired or inexpensively replaced. The saver sub can be equipped with a rubber protector to reduce BOP equipment and casing wear resulting from contact damage with a lower Kelly connection.

 

Straight OD sub

Straight OD sub is used to connect drill stem members that have a similar outside diameter. The drill bit, down hole tools, heavy weight drill pipe and drill pipe can be crossed over using a straight OD sub.

Reduced section sub

Reduced section sub is used to connect drill stem members that have different diameters that warrant the cross-sectional change necessary to accommodate different connections. This sub would be used to crossover large OD drilling tools or a tapered drill collar string.

Oriented bent sub

The oriented sub is a major power deflection tool having a fixed angle (a) deviated from low end thread of the bent sub to axial line of drill stem, the power drill tool under the application of oriented sub give the bit a constant lateral force to ensure that the bit can cut on the well wall laterally and further drill into a curved well trace.

Operation method

1. After the bit and oriented sub are connected and screwed, detecting of the angle between the big water hole of bit and oriented key of oriented sub shall be done:
2. After run in drill tool, calculated out the azimuth of big water hole of bit according to the azimuth of oriented key determined at a single point by drift indicator.
3. Change the big water hole of bit into required azimuth, the lock in rotary and start pump drilling to cut in.
4. During deflecting, taking a way that deflect while lightly pressing and crowning of drill to help deflection.
5. After deflected for 2 to 3 meters, drill in 4 to 5 meters with lightly pressure and rotating slowly.
6. Repeat above operation for several times, when the angle of deviation is up to the expected requirement deflecting in can be done smoothly by reducing of drill pressure and increasing of rotating speed.

Circulating sub

The circulating sub is connected between wellhead pipe string and ground circulating system. When casing is running or finished running, the circulating sub is connected to make fluid circulation. According to the application, the circulating sub is connected between Kelly and casing or between casing and hose. The former is used for fluid circulation during connecting of casing. The later generally is used after connecting of casing.

Construction

The circulating sub during running casing is equipped with casing pin thread on one end or DP thread and DP box thread or union thread on other end.

Circulating sub with drill pipe thread

Circulating sub with hammer union thread.

Wear sub

During drilling operation, serious wear often takes place between drill pipes and casings. Wear sub is used to avoid the wear between drill pipes, tool joint and casings. With features such as compact structure, easy operating, wear sub can prolong the service life of drill pipe and casing, reduce the vibration and trembling of drilling tools, limit the contact friction between metals to metals.

 

Tianhe saver subs consist of a highly wear rubber sleeve, a metal stiffening liner and a sub body. The rubber sleeve is installed in the middle of sub body and some clearance is given to allow sleeve to rotate freely. The rubber sleeves are made of rubber mixtures with good wear resistance.

 

During drilling operation, the rubber sleeve and sub body can make a relative rotation, rubber sleeve O.D is larger than drill pipe tool joint O.D, so the tool joint and drill pipes cannot contact with casing. The rubber sleeve on saver sub will firstly contact with casing. When friction between rubber sleeve and casing takes place, wearing to casing can be reduced due to the rubber sleeve features such as wear and soft, at the same time, consumption to tool joints of drill pipes and drill string tools will be decreased.

When ordering pls specify:

1. Casing size and weight, or O.D of wear sub
2. Connection
3. Drift

Drift is a simple and popular tool for drifting I.D. of casing, tubing, drill pipe and other pipes. It is used to check whether inside diameter of all kinds of pipes are complied with standard, and to determine the max inside diameter to be drifted after deformed. The drift is thus granted as necessary tool in work over operation.

Drift for casings are available in two types:

Sub type drift machined with threads on both top and bottom ends, the top end is connected with drill string, the bottom end is standby.

Bail type drift is composited of gauge plate and connecting rod.

Double bail drift for tubing or drill pipe is usually used on the ground. The shape of drift diameter gauge is a long cylindrical boday with sucker rod thread on both ends to be connected with sucker rod, the drifting is made manually.