14 results about "Underbalanced drilling" patented technology

A method for underbalanced drilling includes drilling into a subterranean geological formation to form a wellbore therein, injecting a foaming agent into the wellbore during drilling at a wellbore pressure that is below a pore pressure of the subterranean geological formation, and transporting drill cuttings formed by the drilling away from the drilling surface in the foam. The foaming agent forms a foam in the wellbore at a drilling surface at a bottom of the wellbore. The foaming agent is an aqueous solution including an ammonium alcohol ether sulfate surfactant.

The invention belongs to the field of unbalanced drilling, and particularly relates to a double-rubber-core rotary sealing device. According to the technical scheme, the double-rubber-core rotary sealing device comprises an upper rotary module, a hoop, a bearing assembly, a lower rotary module and a shell assembly. The upper rotating module comprises an upper shell, an upper rubber core, an oil duct, an upper bearing, a rotating sealing ring and an upper rubber core pressing plate; the bearing assembly comprises a tapered roller bearing, an inner cylinder, a cylindrical roller bearing, a sleeve and a bearing gland; the lower rotating module comprises a lower bearing, a connecting piece and a lower rubber core; the shell assembly comprises an adaptive ring, an upper O-shaped sealing ring, an outer cylinder, a lower O-shaped sealing ring, a shell and a lower cover plate; according to the double-rubber-core rotary sealing device, the upper rubber core and the lower rubber core can be intelligently controlled to alternately work, the service life of the rubber cores is prolonged, the wellhead pressure is controlled for a longer time, and therefore unbalanced drilling is completed, and the drilling speed is increased.

The present application relates to the technical field of geothermal well, particularly to a geothermal well underbalanced drilling, system and prediction and installation method, wherein the geothermal well underbalanced drilling comprises a casing; a drill pipe coaxially arranged with the casing, an outer diameter of the drill pipe being smaller than an inner diameter of the casing, and an annulus existing between the drill pipe and the casing; and a gas injection pipe arranged outside the casing and in communication with the annulus, the gas injection pipe being used for injecting variable flow of gas to mix with drilling fluid in the annulus to form gas-liquid two-phase flow. The gas injection pipe is in communication with the annulus of the casing, the mixed density of the liquid in the annulus is changed by injecting gas into the casing, so that the bottom hole pressure is less than the formation pressure, thereby achieving the effect of underbalanced drilling, improving the drilling speed, and preventing a large amount of drilling fluid from leaking into the formation fracture.

A method for underbalanced drilling includes drilling into a subterranean geological formation to form a wellbore therein, injecting a foaming agent into the wellbore during drilling at a wellbore pressure that is below a pore pressure of the subterranean geological formation, and transporting drill cuttings formed by the drilling away from the drilling surface in the foam. The foaming agent forms a foam in the wellbore at a drilling surface at a bottom of the wellbore. The foaming agent is an aqueous solution including an ammonium alcohol ether sulfate surfactant.

A method of underbalanced drilling includes drilling into a subterranean geological formation to form a wellbore and injecting a foaming agent into the wellbore during drilling at a wellbore pressure that is below a pore pressure of the subterranean geological formation. The foaming agent forms a foam in the wellbore at a drilling surface at a bottom of the wellbore and transports drill cuttings formed by the drilling away from the drilling surface in the foam. The foaming agent is an aqueous solution including a gemini amphiphile dicationic surfactant having a linker and a lipophilic tail.

The utility model relates to the technical field of well drilling, and particularly discloses a blowout prevention device for unbalanced well drilling. Comprising a first valve body and a second valve body; a first connecting plate and a second connecting plate are arranged on one side of the first valve body and one side of the second valve body; the first valve body and the first connecting plate are integrally arranged, and the second valve body and the second connecting plate are integrally arranged. The first air cylinder body and the second air cylinder body are arranged on the two sides of the second main valve body correspondingly and communicate with the second main valve body. A third blowout prevention piece and a fourth blowout prevention piece are arranged in the third air cylinder body and the fourth air cylinder body respectively. The third blowout prevention piece and the fourth blowout prevention piece are combined to form a semi-closed blowout prevention piece; and the first main valve body is communicated with the second main valve body. According to the underbalanced drilling blowout prevention device, the combined design of the totally-closed blowout prevention piece and the semi-closed blowout prevention piece is adopted, and the blowout prevention effect is effectively improved. And the air cylinder body is communicated with the main valve body, so that the balance of working conditions is kept, and the risk of accidental ejection is avoided.

The invention provides a self-pressurization type rotary control head for a vehicle-mounted drilling machine in a coal mine area and a drilling operation method. The rotary control head comprises a hanging ring, a gland, a rubber core, a rotary main shaft, an upper disc bearing, a lower disc bearing, a bearing shell, a lubricating grease injection port, a seal, a lower lubricating grease injection port, a three-way pipe fitting and a connecting flange. The method comprises the step that in the drilling operation process, connecting pipelines of the three-way pipe fitting are different according to different matched drilling technologies of a vehicle-mounted drilling machine in a coal mine area. The problems that the wellhead of the truck-mounted drilling rig in a coal mine area cannot be sealed and works under pressure are solved, the wellhead of the truck-mounted drilling rig has the functions of complete sealing, blowout prevention, pressure building, flow guiding and the like, the truck-mounted drilling rig can be matched with various advanced and efficient drilling technologies such as slurry drilling, underbalanced drilling and air drilling, the application range of the truck-mounted drilling rig is further expanded, and the application range of the truck-mounted drilling rig is expanded. The overall performance of the truck-mounted drilling rig is improved.

The invention relates to the technical field of geothermal wells, in particular to a geothermal well underbalanced drilling well and system and a prediction and installation method. The drill rod and the casing pipe are coaxially arranged, the outer diameter of the drill rod is smaller than the inner diameter of the casing pipe, and an annulus exists between the drill rod and the casing pipe; and the gas injection pipe is arranged on the outer side of the casing pipe and communicates with the annulus, and the gas injection pipe is used for injecting variable-flow gas to be mixed with the drilling fluid in the annulus to form gas-liquid two-phase flow. The gas injection pipe is communicated with the annulus of the casing pipe, and the mixing density of liquid in the annulus is changed by injecting gas into the casing pipe, so that the well bottom pressure is smaller than the formation pressure, the unbalanced drilling effect is achieved, the drilling speed can be increased, and a large amount of drilling fluid can be prevented from leaking into formation cracks.

This invention discloses a method and apparatus for reducing the bottom-hole circulating temperature of deep shale gas horizontal wells, relating to the field of drilling engineering technology. It addresses the technical problem of unsatisfactory cooling effects when using existing surface cooling methods. The method includes the following steps: Step S1: Obtain the three-pressure profile of the well to be drilled and obtain the underpressure value range; Step S2: Determine the underbalanced drilling process based on the underpressure value range; Step S3: Obtain first relationship information and predict the bottom-hole circulating temperature of the well to be drilled. Based on the bottom-hole circulating temperature, the first relationship information, the three-pressure profile, and the underbalanced drilling process, optimize the drilling fluid density in the drilling process. This invention can effectively reduce the bottom-hole circulating temperature during deep shale gas drilling, ensure stable instrument operation, reduce the number of tripping operations, and guarantee efficient drilling of horizontal wells.

The present invention relates to a blowout prevention system and method for a rotary blowout preventer rubber core, and to the technical field of underbalanced drilling and pressure-controlled drilling equipment in the drilling industry; it includes a sealing rubber core, on which a protective sleeve is provided; a rotary blowout preventer rubber core blowout prevention system is provided on the basis of the sealing rubber core, including a rotary blowout preventer, the rotary blowout preventer includes a shell and a top cover, a monitoring unit is provided in the shell, and a protective unit is provided at the bottom of the sealing rubber core. In the present invention, the monitoring unit can monitor the sealing rubber core, and when the sealing rubber core is subjected to greater wear during operation, it will issue an early warning reminder before it is unable to start sealing around the drilling tool, and at the same time, it will prompt that the sealing rubber core needs to be replaced; secondly, the protective unit can wipe the surface of the drilling tool to reduce particles on the surface of the drilling tool, thereby further delaying the wear time of the sealing rubber core and indirectly increasing its service life.

The present invention discloses a method for predicting reservoir damage in underbalanced drilling of infill wells coupled with a geomechanical model, and relates to the technical field of oil and gas drilling engineering. The present invention comprises the following steps: step (1), collecting well logging, mud recording and seismic data, and establishing a three-dimensional fine geological model in combination with the finite element method; step (2), using the well seismic data in combination with the modeling technology of step (1) to model the original properties of the reservoir, and establish a three-dimensional geomechanical model with reservoir and mechanical properties. The present invention describes in detail the characteristics of energy-depleted formations due to long-term mining by combining the geomechanical model with experimental results specifically conducted on old well areas. This method enables the model to accurately reflect actual geological data, ensuring the high accuracy and reliability of the analysis results.

A method of underbalanced drilling includes drilling into a subterranean geological formation to form a wellbore and injecting a foaming agent into the wellbore during drilling at a wellbore pressure that is below a pore pressure of the subterranean geological formation. The foaming agent forms a foam in the wellbore at a drilling surface at a bottom of the wellbore and transports drill cuttings formed by the drilling away from the drilling surface in the foam. The foaming agent is an aqueous solution including a gemini amphiphile dicationic surfactant having a linker and a lipophilic tail.

The present disclosure relates to systems and methods for real-time calculations of a productivity index and a rate-integral productivity index of a well in underbalance drilling. The systems and methods use real-time data received from the well to calculate the productivity index and the rate-integral productivity index of the well. The systems and methods use the productivity index and the rate-integral productivity index to generate visualizations of the well and provide recommendations for the well.

In general, in one aspect, embodiments disclosed herein relate to a method for optimizing underbalanced drilling according to depth of damage. The method includes collecting in situ conditions, well conditions, and formation properties of a subterranean area of interest, calculating changes of in situ stresses induced by a pressure drop inside the wellbore, creating an underbalanced drilling model using the in situ conditions, well conditions, and formation properties, modeling the drilling process, extracting and evaluating plastic mechanical damage from the underbalanced drilling model, adjusting a pre-drilling plan based on the depth of plastic mechanical damage, and finally using the modeled drilling process to drill a well. The in situ stresses include a maximum and minimum confining stress. The underbalanced drilling model includes a mechanical simulation of a first area representing rock surrounding the wellbore, and a second area representing rock inside the wellbore.