A flushing element, rock drilling machine and method of providing a flushing space around a shank adapter of a rock drilling machine. The flushing element surrounds the shank adapter passing through it. The flushing element has a feed opening for feeding flushing agent to the flushing space and at least two sealing housings for flushing sealings and wherein the flushing sealings are on opposite axial sides of the flushing space. Furthermore, the flushing element has split configuration whereby it is mountable and demountable in radial direction.

A flushing element, rock drilling machine and method of providing a flushing space around a shank adapter of a rock drilling machine. The flushing element surrounds the shank adapter passing through it. The flushing element has a feed opening for feeding flushing agent to the flushing space and at least two sealing housings for flushing sealings and wherein the flushing sealings are on opposite axial sides of the flushing space. Furthermore, the flushing element has split configuration whereby it is mountable and demountable in radial direction.

A shank adapter, rock drilling machine and method of mounting a shank adapter of a rock drilling machine inside a slide bearing element. The shank adapter includes a coupling head and a rotation portion at its opposite ends, and a flushing portion located therebetween. Outer diameters of the coupling head and the rotation portion are both greater than outer diameters of portions of the shank adaptor located therebetween.

Provided are systems and methods for drilling a horizontally-oriented well having a sigmoid-shaped wellbore including an upper sigmoid portion having a downward curving wellbore trajectory and a lower sigmoid portion having an upward curving wellbore trajectory. The upper sigmoid portion having a first trajectory having a generally horizontal gradient at an entry point of the wellbore and that increases in downward gradient to a vertical gradient at an inflection point. The lower sigmoid portion having a second trajectory that includes the vertical gradient at the inflection point and that decreases in downward gradient to a generally horizontal gradient at a horizontal transition point of the wellbore.

Provided are systems and methods for drilling a horizontally-oriented well having a sigmoid-shaped wellbore including an upper sigmoid portion having a downward curving wellbore trajectory and a lower sigmoid portion having an upward curving wellbore trajectory. The upper sigmoid portion having a first trajectory having a generally horizontal gradient at an entry point of the wellbore and that increases in downward gradient to a vertical gradient at an inflection point. The lower sigmoid portion having a second trajectory that includes the vertical gradient at the inflection point and that decreases in downward gradient to a generally horizontal gradient at a horizontal transition point of the wellbore.

Provided are systems and methods for drilling a horizontally-oriented well having a sigmoid-shaped wellbore including an upper sigmoid portion having a downward curving wellbore trajectory and a lower sigmoid portion having an upward curving wellbore trajectory. The upper sigmoid portion having a first trajectory having a generally horizontal gradient at an entry point of the wellbore and that increases in downward gradient to a vertical gradient at an inflection point. The lower sigmoid portion having a second trajectory that includes the vertical gradient at the inflection point and that decreases in downward gradient to a generally horizontal gradient at a horizontal transition point of the wellbore.

Provided are systems and methods for drilling a horizontally-oriented well having a sigmoid-shaped wellbore including an upper sigmoid portion having a downward curving wellbore trajectory and a lower sigmoid portion having an upward curving wellbore trajectory. The upper sigmoid portion having a first trajectory having a generally horizontal gradient at an entry point of the wellbore and that increases in downward gradient to a vertical gradient at an inflection point. The lower sigmoid portion having a second trajectory that includes the vertical gradient at the inflection point and that decreases in downward gradient to a generally horizontal gradient at a horizontal transition point of the wellbore.

A downhole oscillation tool includes a Moineau-type positive displacement pulse motor and a valve assembly for use in a drill string. The pulse motor includes a rotor configured to nutate within the bore of a stator. The rotor has at least two helical lobes that extend the length of the rotor, and the stator bore defines at least three helical lobes that extend the length of the stator. The valve assembly includes a first valve plate connected to the bottom end of the rotor and abuts the second valve plate to form a sliding seal. The second valve plate is fixedly coupled to the stator and remains stationary. First valve ports extend axially through the first valve plate, and second valve ports extend axially through the second valve plate. The first valve ports and second valve ports intermittently overlap as the first valve plate slides across the second valve plate to create pulses in the drilling fluid which is pumped through the tool to power the motor and valve assembly. The tool can generate pulses of different amplitudes and different wavelengths in each rotational cycle. The tool further includes a drop ball assembly configured to activate and deactivate the tool.

A downhole oscillation tool includes a Moineau-type positive displacement pulse motor and a valve assembly for use in a drill string. The pulse motor includes a rotor configured to nutate within the bore of a stator. The rotor has at least two helical lobes that extend the length of the rotor, and the stator bore defines at least three helical lobes that extend the length of the stator. The valve assembly includes a first valve plate connected to the bottom end of the rotor and abuts the second valve plate to form a sliding seal. The second valve plate is fixedly coupled to the stator and remains stationary. First valve ports extend axially through the first valve plate, and second valve ports extend axially through the second valve plate. The first valve ports and second valve ports intermittently overlap as the first valve plate slides across the second valve plate to create pulses in the drilling fluid which is pumped through the tool to power the motor and valve assembly. The tool can generate pulses of different amplitudes and different wavelengths in each rotational cycle. The tool further includes a drop ball assembly configured to activate and deactivate the tool.

Provided are systems and methods for drilling a horizontally-oriented well having a sigmoid-shaped wellbore including an upper sigmoid portion having a downward curving wellbore trajectory and a lower sigmoid portion having an upward curving wellbore trajectory. The upper sigmoid portion having a first trajectory having a generally horizontal gradient at an entry point of the wellbore and that increases in downward gradient to a vertical gradient at an inflection point. The lower sigmoid portion having a second trajectory that includes the vertical gradient at the inflection point and that decreases in downward gradient to a generally horizontal gradient at a horizontal transition point of the wellbore.