Abstract: The disclosure generally refers to compositions and methods for treating subterranean formations that improve the recovery of hydrocarbons from the subterranean formations. The compositions include positively and negatively charged nanoparticles suspended in a carrier fluid that is not a drilling fluid and is free of cement and foaming agents. The populations of nanoparticles may be of different sizes, different materials, and comprise different ratios. The composition may also include: surface-active agents, such as surfactants, polymers; detergents; crystal modifiers; stabilizers, or hydronium. In some embodiments, the surface-active agents may bind to the surface of the positively or negatively charged nanoparticles. A subterranean formation may then be injected with the composition.

Abstract: The disclosure generally refers to compositions and methods for treating subterranean formations that improve the recovery of hydrocarbons from the subterranean formations. The compositions include positively and negatively charged nanoparticles suspended in a carrier fluid that is not a drilling fluid and is free of cement and foaming agents. The populations of nanoparticles may be of different sizes, different materials, and comprise different ratios. The composition may also include: surface-active agents, such as surfactants, polymers; detergents; crystal modifiers; stabilizers, or hydronium. In some embodiments, the surface-active agents may bind to the surface of the positively or negatively charged nanoparticles. A subterranean formation may then be injected with the composition.

Abstract: The disclosure generally refers to compositions and methods for treating subterranean formations that improve the recovery of hydrocarbons from the subterranean formations. The compositions include positively and negatively charged nanoparticles suspended in a carrier fluid that is not a drilling fluid and is free of cement and foaming agents. The populations of nanoparticles may be of different sizes, different materials, and comprise different ratios. The composition may also include: surface-active agents, such as surfactants, polymers; detergents; crystal modifiers; stabilizers, or hydronium. In some embodiments, the surface-active agents may bind to the surface of the positively or negatively charged nanoparticles. A subterranean formation may then be injected with the composition.

Abstract: A method is disclosed for adaptively controlling an engine system of a motor vehicle comprising the steps of evaluating the outputs from angular position sensors associated with inlet and exhaust camshafts of an engine of the engine system to establish whether differences between the currently measured positions and previously saved positions are the result of elongation of an endless drive used to drive the camshafts or due to some other reason. If it is confirmed that the differences are due to elongation of the endless drive then the measured values of angular position are used in the control of a number of engine functions.

Abstract: Methods and systems are provided for controlling a variable camshaft timing system. In one example, a method may include actuating a camshaft phaser with a camshaft duty cycle determined based on a sampled camshaft position and an estimated camshaft position, the estimated camshaft position determined based on a previously determined camshaft duty cycle.

Abstract: Methods and systems are provided for controlling a variable camshaft timing system. In one example, a method may include actuating a camshaft phaser with a camshaft duty cycle determined based on a sampled camshaft position and an estimated camshaft position, the estimated camshaft position determined based on a previously determined camshaft duty cycle.

Abstract: A method is disclosed for adaptively controlling an engine system of a motor vehicle comprising the steps of evaluating the outputs from angular position sensors associated with inlet and exhaust camshafts of an engine of the engine system to establish whether differences between the currently measured positions and previously saved positions are the result of elongation of an endless drive used to drive the camshafts or due to some other reason. If it is confirmed that the differences are due to elongation of the endless drive then the measured values of angular position are used in the control of a number of engine functions.

Abstract: Systems and methods for modifying oil pressure for a variable cam timing system are provided. In one example approach, a method comprises, in response to an operating condition, adjusting a valve coupled to a hydraulic variable camshaft timing actuator to initiate camshaft phasing and adjusting an oil pressure supplied to the valve based on a camshaft phaser position. If a camshaft phaser locking pin is in a home position, the method may further comprise reducing the oil pressure supplied to the valve for a predetermined time interval to a threshold amount to unlock the locking pin but not move the camshaft phaser and then increasing the oil pressure supplied to the valve to move the camshaft phaser.

Abstract: Systems and methods for modifying oil pressure for a variable cam timing system are provided. In one example approach, a method comprises, in response to an operating condition, adjusting a valve coupled to a hydraulic variable camshaft timing actuator to initiate camshaft phasing and adjusting an oil pressure supplied to the valve based on a camshaft phaser position. If a camshaft phaser locking pin is in a home position, the method may further comprise reducing the oil pressure supplied to the valve for a predetermined time interval to a threshold amount to unlock the locking pin but not move the camshaft phaser and then increasing the oil pressure supplied to the valve to move the camshaft phaser.