Methods for cementing a subterranean wellbore

1. A method for cementing a tubular member within a subterranean wellbore extending from a surface into a subterranean formation and through a hydrocarbon reservoir, the method comprising:

(a) injecting a gas from the surface into an annulus surrounding the tubular member within the wellbore;

(b) flowing cement through a throughbore of the tubular member;

(c) displacing the cement from the throughbore of the tubular member into the annulus; and

(d) reducing a pressure of the gas in the annulus during (c), wherein (d) further comprises:

(d1) maintaining a fluid pressure in the annulus equal to or greater than a reservoir pressure of the reservoir; and

(d2) limiting the loss of cement into the subterranean formation to less than about 20 vol %.

2. The method of claim 1 , further comprising:

(e) displacing a portion of a fluid in the annulus downhole of the gas during (a).

3. The method of claim 1 , wherein (a) comprises pressurizing the gas in the annulus to push the gas to a predetermined depth in the annulus.

4. The method of claim 3 , further comprising:

(e) flowing the cement uphole through the annulus to a predetermined location in the annulus during (d), wherein the predetermined depth is based on the predetermined location.

5. The method of claim 1 , wherein the gas injected from the surface into the annulus is an inert gas.

6. The method of claim 5 , wherein the gas injected from the surface into the annulus is nitrogen gas.

7. The method of claim 1 , wherein (c) comprises:

(c1) closing a flow path through a plug disposed within the throughbore of the tubular member;

(c2) pumping fluid into the throughbore uphole of the plug after (c1); and

(c3) pushing the plug toward a lower end of the tubular member during (c2) with the fluid.

8. The method of claim 7 , wherein (c1) comprises:

flowing a dart within the throughbore of the tubular member; and

engaging the dart with a dart seat on the plug.

9. The method of claim 8 , further comprising:

(e) actuating a plurality of spaced open hole packers into engagement with the tubular member and a sidewall of the wellbore after (e).

10. A method for cementing a tubular member within a subterranean wellbore extending from the surface into a subterranean formation and through a hydrocarbon reservoir, the method comprising:

(a) injecting a gas from the surface into an annulus surrounding the tubular member within the wellbore;

(b) pressurizing the gas in the annulus to push a fluid in the annulus downhole to a predetermined depth in the annulus;

(c) flowing cement into a throughbore of the tubular member after (a);

(c) displacing the cement from the throughbore of the tubular member into the annulus; and

(d) bleeding the gas from the annulus during (c), wherein (d) further comprises maintaining a fluid pressure in the annulus equal to or greater than a reservoir pressure of the reservoir.

11. The method of claim 10 , wherein (a) comprises filling the annulus with a gas and pressurizing the gas in the annulus to a predetermined pressure to push the fluid in the annulus downhole to the predetermined depth; and

wherein (d) comprises reducing a pressure of the gas during (c).

12. The method of claim 10 , further comprising:

(e) flowing the cement uphole through the annulus to a predetermined location in the annulus during (d), wherein the predetermined depth is based on the predetermined location.

13. The method of claim 10 , wherein the gas injected into the annulus during (a) is an inert gas.

14. The method of claim 10 , wherein (d) further comprises limiting the loss of cement into the subterranean formation to less than about 50 vol %.

15. The method of claim 10 , wherein the gas injected into the annulus during (a) comprises one or more of a hydrocarbon gas, air, nitrogen, and carbon dioxide.

16. The method of claim 15 , further comprising:

(e) actuating a plurality of spaced open hole packers into engagement with the tubular member and a sidewall of the wellbore after (e).

17. The method of claim 10 , wherein (c) comprises:

(c1) closing a flow path through a plug disposed within the throughbore of the tubular member;

(c2) pumping a fluid into the throughbore above the plug after (c1); and

(c3) displacing the plug toward a lower end of the tubular member during (c2).

18. The method of claim 17 , wherein (c1) comprises:

flowing a dart within the throughbore of the tubular member; and

engaging the dart with a dart seat on the plug.