Progressing cavity pump assembly and method of operation

1. A progressing cavity pump assembly, comprising:

a housing comprising a stator, having a stator bore, the housing adapted to receive a rotor within the stator bore;

a collar assembly, having an inside diameter upset, the collar assembly adapted to connect the housing and a tubing string; and

the rotor having a rotor head axially spaced from a rotor helix, the rotor head having an outer diameter forming a stop, the stop adapted to land on the inside diameter upset, the rotor head adapted to connect with a drive string.

2. The progressing cavity pump assembly of claim 1 , wherein the housing and the collar assembly are relatively axially movable.

3. The progressing cavity pump assembly of claim 1 , wherein the housing and the collar assembly are relatively rotationally movable.

4. The progressing cavity pump assembly of claim 1 , wherein the housing and the collar assembly are welded.

5. The progressing cavity pump assembly of claim 1 , wherein the housing and the collar assembly are threaded.

6. The progressing cavity pump assembly of claim 1 , wherein the housing and the collar assembly are integral.

7. The progressing cavity pump assembly of claim 1 , the collar assembly comprising a coupling.

8. The progressing cavity pump assembly of claim 7 , wherein the diameter of the housing is greater than the diameter of the tubing string.

9. The progressing cavity pump assembly of claim 7 , wherein the diameter of the housing is less than the diameter of the tubing string.

10. The progressing cavity pump assembly of claim 1 , wherein the collar assembly and the housing are proximate.

11. The progressing cavity pump assembly of claim 1 , wherein the collar assembly and the housing are adjacent.

12. The progressing cavity pump assembly of claim 1 , the inside diameter upset comprising a tag shoulder.

13. The progressing cavity pump of claim 12 , the tag shoulder having an axial profile.

14. The progressing cavity pump of claim 13 , the axial profile comprising a taper.

15. The progressing cavity pump assembly of claim 1 , the inside diameter upset forming a coupling tag bore, the coupling tag bore adapted to allow the threading of the rotor through the coupling tag bore.

16. The progressing cavity pump assembly of claim 15 , the coupling tag bore timed to the stator bore to allow insertion of the rotor.

17. The progressing cavity pump assembly of claim 16 , the coupling tag bore and the stator bore forming a pathway, the pathway adapted to movably receive the rotor.

18. The progressing cavity pump assembly of claim 17 , wherein the pathway is adapted to receive the rotor in a rotating threading motion.

19. A method of operating a progressing cavity pump assembly, comprising:

providing a tubing string;

providing a housing comprising a stator, a collar assembly, timed to the stator, connected with the housing, the collar assembly having an inside diameter upset;

connecting the tubing string and the housing;

installing the tubing string and the housing into a wellbore;

providing a drive string;

providing a rotor having a rotor head axially spaced from a rotor helix, the rotor head having an outer diameter forming a stop;

connecting the rotor and the drive string;

installing the rotor and the drive string into the wellbore by rotatably threading the rotor into the stator through the collar assembly until the stop lands on the inside diameter upset; and

lifting the rotor a selected distance by lifting the drive string from surface.

20. The method of claim 19 , further comprising:

rotating the drive string, thereby rotating the rotor within the stator to pump fluids from the wellbore up the tubing string.

21. A method of timing a progressing cavity pump assembly comprising:

providing a housing comprising a stator, having a stator bore;

providing a collar assembly, the collar assembly having an inside diameter upset;

movably connecting the collar assembly and the housing;

providing a timing piece, the timing piece having a timing helix adapted to fit the stator bore;

selectively adjusting the relative position of the collar assembly and the housing to form a pathway substantially corresponding to the timing helix;

providing a rotor having a rotor head axially spaced from a rotor helix, the rotor head having an outer diameter forming a stop, and installing the rotor into the housing by threading the rotor into the stator through the collar assembly until the stop lands on the inside diameter upset; and

fixing the relative position of the collar assembly and the housing.

22. The method of claim 21 , wherein the timing piece comprises a timing jig.

23. The method of claim 21 , wherein the timing piece comprises the rotor.