Geophysical prospecting may be achieved using borehole seismic data and processing velocity seismic profiles using downward continuation to simulate the seismic source being at the depth of the borehole receivers. Such methods may involve collecting seismic data for a subterranean formation with at least one borehole receiver; grouping the seismic data into a one common receiver gather corresponding to each borehole receiver; performing a downward continuation on at least one of the common receiver gathers to produce corresponding downward continued common receiver gathers; performing a normal moveout analysis on at least one of the downward continued common receiver gathers to produce corresponding semblance velocity spectra; and analyzing at least one of the semblance velocity spectra for a zone of interest in the subterranean formation.

A cutting head includes a main body that is attachable to an ice drill shaft at a top side. The main body includes a bottom side that has a bottom peripheral surface. The cutting head includes at least one cutting edge that is disposed on the main body. The cutting edge is configured to perform a cutting operation at the bottom side of the main body. The cutting head includes a cutting rate control pad that is disposed on the bottom side of the main body. The cutting rate control pad extends away from the bottom peripheral surface.

A method for developing a subterranean field includes: receiving a representation of a rock surface in the subterranean field, the representation having a boundary; defining a set of grid planes over the representation; defining a plurality of core nodes at intersections of the grid planes that are within the boundary; defining core lines to connect each core node with each adjacent core node along the set of grid planes; defining a plurality of plane nodes on the grid planes where each grid plane intersects the boundary; defining plane lines to connect each plane node with each adjacent plane node along the grid planes; defining outlier nodes at each vertex of the boundary; and defining boundary lines connecting each of the plane nodes and each of the outlier nodes along the boundary. The method further includes operating equipment using at least one definition in order to develop the subterranean field.

A method for developing a subterranean field includes: receiving a representation of a rock surface in the subterranean field, the representation having a boundary; defining a set of grid planes over the representation; defining a plurality of core nodes at intersections of the grid planes that are within the boundary; defining core lines to connect each core node with each adjacent core node along the set of grid planes; defining a plurality of plane nodes on the grid planes where each grid plane intersects the boundary; defining plane lines to connect each plane node with each adjacent plane node along the grid planes; defining outlier nodes at each vertex of the boundary; and defining boundary lines connecting each of the plane nodes and each of the outlier nodes along the boundary. The method further includes operating equipment using at least one definition in order to develop the subterranean field.

A downhole drilling assembly includes a drill string having an inner fluid passageway. A fluid motor disposed within the drill string has a rotor operable to rotate relative to a stator in response to a circulating fluid received via the inner fluid passageway. A drive shaft and drill bit are operably associated with and operable to rotate with the rotor. A hydraulically actuated clutch disposed within the drill string has a first configuration, wherein a first clutch assembly is disengaged from a second clutch assembly such that the drive shaft and drill bit rotate relative to the drill string and, a second configuration, wherein the first clutch assembly engages the second clutch assembly responsive to hydraulic pressure generated by rotation of the drill string such that the drive shaft and drill bit rotate with the drill string.

A formation testing tool which performs the dual function of fracturing and in-situ proppant placement. The testing tool houses proppant slurry having proppant and fracture fluid therein, and a probe which seals against the wellbore wall. During operation, the probe seals against the wellbore wall whereby fluid communication may take place. Using a pump aboard the testing tool, the fracture fluid is forced through the probe and into the formation to produce the fractures. The testing tool, which has a pressurized compartment, then injects the proppant into the fractures.

The present invention provides a method for selecting the location of a stimulating well, comprising the steps of conducting a geological study of a field containing a geothermal hydrothermal resource by operating geological useful equipment, determining a maximum horizontal stress line within said field by means of a device, generating a map of existing wells including a plurality of sub-commercial wells within said field relative to said maximum horizontal stress line, measuring a distance between each of said sub-commercial wells and the maximum horizontal stress line, determining that those sub-commercial wells aligned with, or located relatively close to the maximum horizontal stress line are stimulatable, and selecting a location of a stimulating well for stimulating the stimulatable well that is separated less than an anticipated fracture propagating distance from said stimulatable well.

The present invention provides a method for selecting the location of a stimulating well, comprising the steps of conducting a geological study of a field containing a geothermal hydrothermal resource by operating geological useful equipment, determining a maximum horizontal stress line within said field by means of a device, generating a map of existing wells including a plurality of sub-commercial wells within said field relative to said maximum horizontal stress line, measuring a distance between each of said sub-commercial wells and the maximum horizontal stress line, determining that those sub-commercial wells aligned with, or located relatively close to the maximum horizontal stress line are stimulatable, and selecting a location of a stimulating well for stimulating the stimulatable well that is separated less than an anticipated fracture propagating distance from said stimulatable well.

Activation modules for selectively sealing entrances to inner barrels of coring tools may include an activator body sized and configured to obstruct the entrance to the inner barrel when the activation module is in a first state and to release the entrance to the inner barrel when the activation module is in a second state. A sealing element may be located at a periphery of the activator body, and may be configured to form a seal between at least a portion of an interior of the inner barrel and at least a portion of an exterior of the inner barrel when the activation module is in the first state and to disengage the seal when the activation module is in the second state.

The present invention relates to a drilling composition comprising an organic phase having at least one linear or branched, cyclic or non-cyclic, saturated hydrocarbon, at least one ester, water or aqueous phase, and at least one additive.

The present invention additionally relates to the use and preparation of the drilling composition, to a drilling system, to a process for making a borehole, to a process for conveying cuttings, to a process for treating a drill head, and to a process for production of oil and/or gas.