Method of dynamically killing a well blowout
AssigneeMobil Oil Corporation
InventorElmo M. Blount
Life of this patent
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Abstract
A process for dynamically killing a well blowout by means of a relief well. A low density fluid is pumped down the relief well and into the blowout well at a rate to produce a frictional pressure loss in the blowout well which when added to the hydrostatic pressure in the blowout well is greater than the static formation pressure but less than the formation fracturing pressure. Injection of the low density fluid is continued until the blowout well goes from two-phase to single-phase flow. Thereafter, a high density fluid such as a drilling mud is pumped down the relief well and into the blowout well. This fluid produces a hydrostatic pressure in the blowout well which is greater than the static formation pressure.
Claims3
In a method of killing a blowout in a well penetrating a subterranean gas-producing formation by the introduction of fluid into said blowout well through a relief well including a tubing string and casing defining an annulus and penetrating said formation and in fluid communication with said blowout well, the steps comprising:
- (a) introducing into said relief well a fluid having a low density which produces a hydrostatic pressure component which is less than the static pressure of said formation,
- (b) pumping said low density fluid down the annulus of said relief well and into said blowout well at a flow rate to produce a frictional pressure component in said blowout well whereby the sum of said frictional pressure component and said hydrostatic pressure component is greater than the static formation pressure but less than the formation fracturing pressure,
- (c) introducing into said tubing string a fluid having a density which produces a hydrostatic head in said tubing string which is less than the static formation pressure and maintaining said fluid in said tubing string under conditions such that the pressure differential from the wellhead to the bottom of said tubing string is substantially equal to said hydrostatic head,
- (d) measuring the wellhead pressure of said tubing string during the injection of said low density fluid down said annulus to monitor the bottomhole pressure in said relief well,
- (e) continuing the injection of said first fluid as set forth in step (b) down said relief well and into said blowout well to block the flow of gas from said formation into said blowout well,
- (f) introducing into said relief well a fluid having a sufficiently high density to produce a hydrostatic pressure which is greater than the static formation pressure, and
- (g) pumping said high density fluid down the annulus of said relief well and into said blowout well at a flow rate which is less than the maximum flow rate of step (b) to produce a frictional pressure loss in said blowout well whereby the sum of said frictional pressure loss and said hydrostatic pressure for said high density fluid is less than the formation fracturing pressure.
Dependencies are inferred from the claim text.