Abstract: A novel passive flow restrictor attached outside the tubing in an oil well and positioned below casing perforations, causing fluid flow from an oil reservoir formation to at least partially flow through a narrow annular space between the flow restrictor and the casing before entering the tubing. The flow resistance is thereby defined in part by the length of the annular space, which is easily adjusted by lowering or raising the tubing within the casing. The flow restrictor and methods of using thereof are especially advantageous for maximizing oil production in thin oil rim gas reservoir as well as with other oil wells with high Gas-to-Oil Ratio.

Abstract: A method for maximizing oil production rate from an oil well with high gas-to-oil ratio comprising a step of calculating an optimal bottomhole pressure and determining a well-specific geometry for a flow restrictor located at the bottomhole region of the oil well. The flow restrictor comprises at least a first stage tube and a second stage tube and has a fixed geometry calculated to cause self-regulation of the oil flow conditions so as to maintain the bottomhole pressure at a stable equilibrium level causing maximum oil rate production and increasing ultimate oil recovery from an oil well.

Abstract: A method for determining formation pressure during exploratory drilling for oil includes generating a series of negative pressure shock waves at successively increasing well pressures to characterize gas kick forming at the bottom of a well. Once the lower end of the gas kick has been formed, the well pressure level as detected by a pressure sensor near the surface of the well is used to calculate the formation pressure along with the weight of the fluid column located in the well.

Abstract: A method for determining formation pressure during exploratory drilling for oil includes generating a series of negative pressure shock waves at successively increasing well pressures to characterize gas kick forming at the bottom of a well. Once the lower end of the gas kick has been formed, the well pressure level as detected by a pressure sensor near the surface of the well is used to calculate the formation pressure along with the weight of the fluid column located in the well.

Abstract: Methods and devices for restoring control of at an offshore oil well following an uncontrolled fluid release after an explosion include lowering through a riser of successive flow restricting inserts into the oil well to gradually reduce the uncontrolled fluid release. Flow restricting inserts may be inserted in parallel or in series with each other. Following attachment of the riser to the oil well, provisions are made to restore oil production from the well. Flow restricting inserts may further be used to adjust flow resistance from the well in order to optimize oil production. Passages between the riser and the flow restricting inserts may also be used to form a gas lift in order to maximize production of oil from the well.

Abstract: Methods and devices for restoring control of at an offshore oil well following an uncontrolled fluid release after an explosion include lowering through a riser of successive flow restricting inserts into the oil well to gradually reduce the uncontrolled fluid release. Flow restricting inserts may be inserted in parallel or in series with each other. Following attachment of the riser to the oil well, provisions are made to restore oil production from the well. Flow restricting inserts may further be used to adjust flow resistance from the well in order to optimize oil production. Passages between the riser and the flow restricting inserts may also be used to form a gas lift in order to maximize production of oil from the well.

Abstract: A method and an apparatus for killing of uncontrolled oil fountain include a series of rods with the first rod having the smallest diameter and successive rods having increasing diameters. Such telescopic assembly of rods is lowered into the well to cause gradual reduction in cross-sectional area available for oil flow discharge. Once sufficiently large rods are lowered into the well, the oil fountain discharge will be greatly diminished. Final sealing may be accomplished by pumping cement into a space formed between the well pipe and the rod assembly. A novel system for aligning the rods to the center of the well is also described.

Abstract: A method for killing an uncontrolled fountain in an oil well following a blowout includes a serial lowering into the well of narrow flow restricting rods, each rod being sufficiently small in diameter to allow its insertion against a high well pressure urging the rods out of the well. Each subsequent rod reduces the cross-sectional area of the well and gradually reduces the flow of fluid discharge out of the well. Once the fountain is sufficiently reduced, the well may be killed using traditional sealing techniques such as pumping cement down the well.

Abstract: Acoustics-based methods and devices to characterize a gas kick during drilling an oil, gas, or gas condensate well are described. A pressure wave may be generated by abruptly changing the drilling mud pressure in the well, for example at the well head. The pressure wave is allowed to travel down the well, reflect from the well bottom and reach the well head again. Pressure is monitored during this process and a pressure peak is identified. The gas kick is characterized using the width of the pressure peak and time elapsed from the onset of pressure change and appearance of the peak. Negative pressure wave is preferred and may be generated by opening of a fast-acting valve located in the outlet pathway of the drilling mud fluid.

Abstract: Acoustics-based methods and devices to characterize a gas kick during drilling an oil, gas, or gas condensate well are described. A pressure wave may be generated by abruptly changing the drilling mud pressure in the well, for example at the well head. The pressure wave is allowed to travel down the well, reflect from the well bottom and reach the well head again. Pressure is monitored during this process and a pressure peak is identified. The gas kick is characterized using the width of the pressure peak and time elapsed from the onset of pressure change and appearance of the peak. Negative pressure wave is preferred and may be generated by opening of a fast-acting valve located in the outlet pathway of the drilling mud fluid.

Abstract: A bottomhole tool and a method for optimizing oil production rate from an oil well with high gas-to-oil ratio and stabilizing thereof in case of occurrence of a gas cone or gas skin conditions are disclosed. The resistance of the adjustable multi-stage flow resistor is determined by a position of a telescoping needle, which in turn is defined by a driving means including a motor and a gearbox. The motor is driven via a cable from a surface by a control means adapted to receive information about the bottomhole parameters from local sensors via a sensor cable. Methodology explaining the principles of maintaining well stability is also disclosed. Automatic adjustment of the bottomhole pressure is maintained over a wide range of operating parameters throughout the life of the well to maximize its oil output.

Abstract: A bottomhole tool and a method for optimizing oil production rate from an oil well with high gas-to-oil ratio and stabilizing thereof in case of occurrence of a gas cone or gas skin conditions are disclosed. The resistance of the adjustable multi-stage flow resistor is determined by a position of a telescoping needle, which in turn is defined by a driving means including a motor and a gearbox. The motor is driven via a cable from a surface by a control means adapted to receive information about the bottomhole parameters from local sensors via a sensor cable. Methodology explaining the principles of maintaining well stability is also disclosed. Automatic adjustment of the bottomhole pressure is maintained over a wide range of operating parameters throughout the life of the well to maximize its oil output.

Abstract: A method for optimizing oil production rate from an oil well with high gas-to-oil ratio is disclosed to include modeling an Inflow Performance Relationship curve and calculating an optimal level of bottomhole pressure to be higher than zero. Maintaining the bottomhole pressure at that calculated optimum level by using a bottomhole tool of the invention or other known means such as gas injection provides for maximum oil recovery from a given well. The bottomhole tool includes a multi-stage flow resistor and a needle moved in and out of the resistor by a spring-biased piston responsive to a difference in pressure between a bottomhole pressure and a pipe pressure. Automatic adjustment of the bottomhole pressure is maintained over a wide range of operating parameters throughout the life of the well.

Abstract: A method for optimizing oil production rate from an oil well with high gas-to-oil ratio is disclosed to include modeling an Inflow Performance Relationship curve and calculating an optimal level of bottomhole pressure to be higher than zero. Maintaining the bottomhole pressure at that calculated optimum level by using a bottomhole tool of the invention or other known means such as gas injection provides for maximum oil recovery from a given well. The bottomhole tool includes a multi-stage flow resistor and a needle moved in and out of the resistor by a spring-biased piston responsive to a difference in pressure between a bottomhole pressure and a pipe pressure. Automatic adjustment of the bottomhole pressure is maintained over a wide range of operating parameters throughout the life of the well.