Frac head including a mixing chamber

• US 20080083530A1
• Filed: 10/06/2006
• Published: 04/10/2008
• Est. Priority Date: 10/06/2006
• Status: Active Grant

• Current Assignee: Smith International Incorporated (Schlumberger NV)
• Original Assignee: Boyd's Bit Service Incorporated
• Inventors: Boyd, Mark Dwayne
• Granted Patent: US 7,478,673 B2
• Time in Patent Office: Days
• US Class Current: 166/90.1
• CPC Class Codes: E21B 33/068 having provision for introducing objects or fluids into, or removing objects from, wells cementing-heads E21B33/05
• CPC Class Codes: E21B 43/2607 Surface equipment specially adapted for fracturing operations

Abstract

An improved frac head includes a mixing chamber located in an internal bore downstream of an intercept between the side ports and the internal bore and upstream of a tapered vortex portion of the bore. The tapered vortex reduces the diameter of the bore from a first diameter to a second diameter. The length of the mixing chamber (along the longitudinal axis of the frac head) is advantageously greater than the first diameter. The ratio of the first diameter to the second diameter is further advantageously greater than 1.5. Frac heads in accordance with this invention tend to undergo significantly reduced erosion as compared to frac heads of the prior art thereby improving service life. The invention also advantageously obviates the need for deployment of erosion resistant sleeves (or other wear resistant liners) in the interior of the frac head.

Claims

1. A frac head comprising:

a frac head body including an upstream end, a downstream end, and an internal bore, the internal bore having a first diameter at the upstream end and a second diameter at the downstream end, the first diameter being larger than the second diameter, the internal bore further having a tapered region between the upstream and downstream ends;

a plurality of side ports deployed about the frac head body, the side ports intercepting the internal bore upstream of the tapered region and being disposed to produce fluid flow in a downstream direction; and

an internal mixing chamber located within the internal bore between the side ports and the tapered region.

2. The frac head of claim 1, wherein the internal mixing chamber has a diameter substantially equal to the first diameter.

3. The frac head of claim 1, wherein a length of the mixing chamber along a longitudinal axis of the frac head is greater than the first diameter.

4. The frac head of claim 3, wherein the length of the mixing chamber is at least 2 times the first diameter.

5. The frac head of claim 1, wherein the first diameter is at least 1.5 times the second diameter.

6. The frac head of claim 1, wherein the first diameter is at least 1.5 times an inner diameter of the side ports.

7. The frac head of claim 1, wherein the tapered region has a taper in the range from about 2 to about 3 inches of diameter reduction per foot of length of the tapered region.

8. The frac head of claim 1, further comprising a top port deployed on the upstream end of the frac head body and substantially coaxially with the internal bore.

9. The frac head of claim 1, comprising first, second, and third frac head body portions, the first body portion including a top port, the second body portion including the plurality of side ports and an internal bore having the first diameter, the third body portion including a tapered region located downstream of a first straight bore and upstream of a second straight bore, the first straight bore having the first diameter and the second straight having the second diameter.

10. The frac head of claim 1, wherein at least one inner surface of the frac head includes a tungsten carbide erosion resistant coating.

11. A frac head comprising:

a frac head body including an upstream end, a downstream end, and an internal bore, the internal bore having a first diameter at the upstream end and a second diameter at the downstream end, the first diameter being larger than the second diameter, the internal bore further having a tapered region between the upstream and downstream ends;

a plurality of side ports deployed about the frac head body, the side ports having an intercept with the internal bore that is upstream of the tapered region, the side ports disposed to produce fluid flow in a downstream direction; and

a longitudinal distance between the intercept and the tapered region being greater than the first diameter.

12. The frac head of claim 11, wherein the longitudinal distance is at least 2 times the first diameter.

13. The frac head of claim 11, wherein the first diameter is at least 1.5 times the second diameter.

14. The frac head of claim 11, wherein the first diameter is at least 1.5 times an inner diameter of the side ports.

15. The frac head of claim 11, wherein the tapered region has a taper in the range from about 2 to about 3 inches of diameter reduction per foot of length.

16. The frac head of claim 11, further comprising a top port deployed on the upstream end of the frac head body and substantially coaxially with the internal bore.

17. The frac head of claim 11, comprising first, second, and third frac head body portions, the first body portion including a top port, the second body portion including the plurality of side ports and an internal bore having the first diameter, the third body portion including the tapered region of the internal bore.

18. A frac head comprising:

a main body portion including an internal bore having a first diameter, the main body portion further including a plurality of side ports deployed thereabout, the side ports inserted into corresponding side bores in the main body portion, the side ports disposed to produce fluid flow in a downstream direction, a longitudinal distance between the side bores and a lower face of the main body being greater than the first diameter;

an upper body portion mechanically coupled to an upstream face of the main body portion, the upper body portion including a top port disposed substantially coaxially with the internal bore; and

a lower body portion mechanically coupled to a downstream face of the main body portion, the lower body including an internal bore having a tapered region that reduces the internal bore from the first diameter to a second diameter.

19. The frac head of claim 18, wherein the longitudinal distance is at least 2 times the first diameter.

20. The frac head of claim 18, wherein the first diameter is at least 1.5 times the second diameter.

21. The frac head of claim 18, wherein the first diameter is at least 1.5 times an inner diameter of the side bores.

22. The frac head of claim 18, wherein the tapered region has a taper in the range from about 2 to about 3 inches of diameter reduction per foot of length.

23. The frac head of claim 20, wherein the lower body portion includes a straight bore upstream of the tapered region, the straight bore having an inner diameter substantially equal to the first diameter.