Spiral Drill Collar

The Spiral Drill Collar is made from AISI 4145H modified alloy steel, and completely meets the requirement of API Spec 7-1 and SY/T5144 Standard. It is a kind of drill collar which adds three dextrogyrate spiral groove on the outer circle of ordinary drill collar when processing, and the purpose is to reduce the area of contact and friction with the well wall, which can effectively prevent the pressure sticking. The single weight of the spiral drill collar is round about 4% lighter than the ordinary drill collar with the same specification, and the shape and thread of the both ends are the same with the drill collar.

OD		Connection	ID	Length±	Chamfering Diameter ±	Length of one spiral ±
79.4	3 1/8	NC23	31.8	9140 or 9450	76.2	679
88.9	3-1/2	NC26	38.1	9140 or 9450	82.9	679
104.8	4 1/8	NC31	50.8	9140 or 9450	100.4	914
114.3	4 1/2	NC31	50.8	9140 or 9450	100.4	914
120.6	4 3/4	NC35	50.8	9140 or 9450	114.7	965
127	5	NC38	57.2	9140 or 9450	121	965
139.7	5 1/2	NC40	57.2	9140 or 9450	132.2	1067
158.8	6 1/4	NC46	71.4	9140 or 9450	144.5	1067
168.3	6 5/8	NC50	71.4	9140 or 9450	154.8	1168
177.8	7	NC50	71.4	9140 or 9450	164.7	1168
196.8	7 3/4	NC50, NC56	71.4	9140 or 9450	185.3	1626
203.2	8	NC56, 6 5/8REG	71.4	9140 or 9450	190.1	1727
209.6	8 1/4	6 5/8REG	71.4	9140 or 9450	195.6	1727
215.9	8 1/2	6 5/8REG	71.4	9140 or 9450	195.6	1727
228.6	9	6 5/8REG	71.4	9140 or 9450	212.7	1829
241.3	9 1/2	7 5/8REG	76.2	9140 or 9450	223.8	1829
254	10	7 5/8REG, 8 5/8REG	76.2	9140 or 9450	237.3	1930
279.4	11	8 5/8REG	76.2	9140 or 9450	266.7	2032