Well drilling system with closed circulation of gas drilling fluid and fire suppression apparatus

In a system for drilling a well into a subterranean earth formation including an elongated drillstem extendable into a wellbore, said wellbore including a wellhead through which said drillstem extends, a closed gaseous drilling fluid circulation system comprising:

• an enclosure operably connected to said wellhead for receiving cuttings laden gaseous drilling fluid from said wellbore;
• a control head operably connected to said wellhead for receiving a portion of said drillstem and for forming a substantially fluid tight seal therewith to prevent escape of drilling fluid from said system;
• and
• a pressure vessel operably connected to said enclosure for receiving cuttings laden drilling fluid from said enclosure, said pressure vessel including an interior space for receiving cuttings laden drilling fluid therein and for separating a substantial portion of drill cuttings solids from said drilling fluid, said pressure vessel including means for discharging substantially cuttings free drilling fluid from said pressure vessel, means for discharging drill cuttings from said pressure vessel from time to time without releasing a substantial quantity of drilling fluid from said pressure vessel to atmosphere, a liquid collection space for receiving liquids entrained with said drilling fluid, discharge port means in communication with said liquid collection space for receiving liquid and drilling fluid and control means for discharging liquid and drilling fluid from said liquid collection space in response to accumulation of a predetermined quantity of liquid in said liquid collection space.

A method for drilling a well into a subterranean earth formation with a drilling system including an elongated drillstem extendable into a wellbore, means for conducting natural gas drill cuttings evacuation fluid through said drillstem into a wellbore annulus formed between said wellbore and said drillstem and means for removing drill cuttings from said drill cuttings evacuation fluid leaving said wellbore, comprising the steps of:

• providing evacuation fluid from a pressure gas conduit connected to one of a gas reservoir, a gas gathering conduit system, and a gas conduit delivery system;
• circulating said evacuation fluid through said wellbore to entrain drill cuttings therein;
• separating drill cuttings from said evacuation fluid;
• and
• discharging cuttings free evacuation fluid to a gas distribution conduit.

In a system for drilling a well into a subterranean earth formation:

• an elongated drillstem extendable into a wellbore forming said well and operable to conduct a gaseous drill cuttings evacuation fluid into said wellbore for evacuating drill cuttings therefrom;
• a wellhead including means forming a seal at said drillstem and an enclosure forming a fluid conducting interior space disposed around said drillstem, said enclosure including a discharge conduit for conducting drill cuttings evacuation fluid from said wellbore through said enclosure;
• a pressure vessel connected to said discharge conduit including means therein for separating particulate solids drill cuttings from gaseous drill cuttings evacuation fluid;
• compressor means operable for discharging pressure gaseous drill cuttings evacuation fluid to said wellbore;
• conduit means interconnecting said compressor means with said pressure vessel for conducting substantially solids free drill cuttings evacuation fluid to said compressor means;
• and
• a fine particle separator device interposed said pressure vessel and said compressor means for separating fine particulate solids from said drill cuttings evacuation fluid.

In a system for drilling a well into a subterranean earth formation:

• an elongated drillstem extendable into a wellbore forming said well and operable to conduct a gaseous drill cuttings evacuation fluid into said wellbore for evacuating drill cuttings therefrom;
• a wellhead including means forming a seal at said drillstem and an enclosure forming a fluid conducting interior space disposed around said drillstem, said enclosure including a discharge conduit for conducting drill cuttings evacuation fluid from said wellbore through said enclosure;
• a pressure vessel connected to said discharge conduit including means therein for separating particulate solids drill cuttings from gaseous drill cuttings evacuation fluid;
• compressor means operable for discharging pressure gaseous drill cuttings evacuation fluid to said wellbore;
• conduit means interconnecting said compressor means with said pressure vessel for conducting substantially solids free drill cuttings evacuation fluid to said compressor means;
• and
• gas-liquid separator means disposed in said drilling system between said pressure vessel and said compressor means.

In a system for drilling a well into a subterranean earth formation:

• an elongated drillstem extendable into a wellbore forming said well and operable to conduct a gaseous drill cutting evacuation fluid into said wellbore for evacuating drill cuttings therefrom;
• a wellhead including means forming a seal at said drillstem and comprising a rotary control head forming a substantially fluid tight seal around a section of said drillstem to prevent flow of said drill cuttings evacuation fluid from said drilling system and an enclosure forming a fluid conducting interior space disposed around said drillstem and operably connected to said control head, said enclosure including a discharge conduit for conducting drill cuttings evacuation fluid from said wellbore through said enclosure;
• a pressure vessel connected to said discharge conduit including means therein for separating particulate solids drill cuttings from gaseous drill cuttings evacuation fluid;
• compressor means operable for discharging pressure gaseous drill cuttings evacuation fluid to said wellbore;
• a source of fluidizable fire extinguishing material;
• and
• fluid discharge nozzle means operable to inject fire extinguishing fluid into said interior space to minimize the ignition of said drill cuttings evacuation fluid in a region of said drilling system near said control head.

In a system for drilling a well into a subterranean earth formation including an elongated drillstem extendable into a wellbore, said wellbore including a wellhead through which said drillstem extends, a closed gaseous drilling fluid circulation system comprising:

• an enclosure operably connected to said wellhead for receiving cuttings laden gaseous drilling fluid from said wellbore;
• a control head operably connected to said wellhead for receiving a portion of said drillstem and for forming a substantially fluid tight seal therewith to prevent escape of drilling fluid from said system;
• and
• a pressure vessel operably connected to said enclosure for receiving cuttings laden drilling fluid from said enclosure, said pressure vessel including an interior space for receiving cuttings laden drilling fluid therein and for separating a substantial portion of drill cuttings solids from said drilling fluid, said pressure vessel including means for discharging substantially cuttings free drilling fluid from said pressure vessel, a plurality of spaced apart baffles disposed in said pressure vessel and forming separate interior spaces therebetween and within said pressure vessel, and means for discharging drill cuttings from said pressure vessel from time to time comprising a discharge conduit in communication with each of said spaces and valve means interposed in said discharge conduits for allowing a quantity of drill cuttings to pass through said discharge conduits without discharging a substantial quantity of drilling fluid from said pressure vessel to atmosphere.

In a system for drilling a well into a subterranean earth formation including an elongated drillstem extendable into a wellbore, said wellbore including a wellhead through which said drillstem extends, a closed gaseous drilling fluid circulation system comprising:

• an enclosure operably connected to said wellhead for receiving cuttings laden gaseous drilling fluid from said wellbore;
• a control head operably connected to said wellhead for receiving a portion of said drillstem and for forming a substantially fluid tight seal therewith to prevent escape of drilling fluid from said system;
• and
• a pressure vessel operably connected to said enclosure and including an inlet conduit in communication with said enclosure for receiving cuttings laden drilling fluid from said enclosure, said pressure vessel including an interior space for receiving cuttings laden drilling fluid therein and for separating a substantial portion of drill cuttings solids from said drilling fluid, a removable wear plate disposed in said interior space, said inlet conduit being directed at said wear plate, access port means formed in said pressure vessel for access to said interior space, said pressure vessel including means for discharging substantially cuttings free drilling fluid from said pressure vessel and means for discharging drill cuttings from said pressure vessel from time to time without releasing a substantial quantity of drilling fluid from said pressure vessel to atmosphere.

In a system for drilling a well into a subterranean earth formation including an elongated drillstem extendable into a wellbore, said wellbore including a wellhead through which said drillstem extends, a closed gaseous drilling fluid circulation system comprising:

• an enclosure operably connected to said wellhead for receiving cuttings laden gaseous drilling fluid from said wellbore;
• a control head operably connected to said wellhead for receiving a portion of said drillstem and for forming a substantially fluid tight seal therewith to prevent escape of drilling fluid from said system;
• a pressure vessel operably connected to said enclosure for receiving cuttings laden drilling fluid from said enclosure, said pressure vessel including an interior space for receiving cuttings laden drilling fluid therein and for separating a substantial portion of drill cuttings solids from said drilling fluid, said pressure vessel including means for discharging substantially cuttings free drilling fluid from said pressure vessel and means for discharging drill cuttings from said pressure vessel from time to time without releasing a substantial quantity of drilling fluid from said pressure vessel to atmosphere;
• separator means disposed between said enclosure and said pressure vessel for separating solids particulates and gaseous drilling fluid from liquids entrained with said drilling fluid;
• and
• conduit means interconnecting said separator means with said pressure vessel for conducting drilling fluid to said pressure vessel.

In a system for drilling a well into a subterranean earth formation, said system including an elongated drillstem extendable into a wellbore penetrating said earth formation and a wellhead operably connected to said wellbore for receiving said drillstem extending therethrough and including means forming a circulation path for drill cuttings evacuation fluid circulated through said drillstem and through an annulus of said wellbore formed between a wellbore wall and said drillstem, the improvement characterized by:

• a member forming a substantially tubular enclosure supported on said wellhead and disposed in said circulation path comprising a generally cylindrical main conduit section and branch conduit section intersecting said main conduit section for conducting cuttings laden evacuation fluid away from said main conduit section;
• an array of nozzles on said member and opening into an interior space formed by said main conduit section, said nozzles being in fluid flow communication which said main conduit section at a point above said branch conduit section and below further well structure, said nozzles being inclined at an acute angle with respect to an interior wall of said main conduit section in a direction toward said further well structure and in a direction of flow of cuttings evacuation fluid and wellbore fluids in the event of uncontrolled flow of fluids from said wellbore through said main conduit section and past said branch conduit section;
• a manifold connected to each of said nozzles;
• and
• a source of fire extinguishing fluid operably connected to said manifold for discharging said fire extinguishing fluid into the flow path of wellbore fluids flowing through said main conduit section without diversion into said branch conduit section to suppress combustion of such wellbore fluids.

In a system for drilling a well into a subterranean earth formation, said system including an elongated drillstem extendable into a wellbore penetrating said earth formation, a wellhead operably connected to said wellbore and means mounted on said wellhead and operable to form a substantially fluid tight seal around said drillstem to prevent wellbore fluids from being discharged from said wellhead along the exterior of said drillstem, the improvement characterized by:

• a member disposed on said wellhead and supporting said means forming said seal, said member including a generally cylindrical main conduit section forming an enclosure and a branch conduit section intersecting said main conduit section for conducting wellbore fluids away from said wellhead at a point between said wellbore and said means forming said seal;
• a plurality of nozzles spaced apart circumferentially about said main conduit section and in communication with an interior space of said main conduit section between said branch conduit section and said means forming said seal, said nozzles being oriented in direction inclined with respect to an interior wall of said main conduit section for directing a flow of fire extinguishing fluid toward said means forming said seal and in the direction of flow of fluids from said wellbore through said main conduit section in the event of failure of said means forming said seal;
• and
• a source of fire extinguishing fluid operably connected to said nozzles for discharging fire extinguishing fluid into said main conduit section to suppress combustion of combustible materials flowing from said wellbore.