Abstract: A coplanar jetting head for well perforating. The apparatus comprises a housing defining a plurality of jetting openings therein. The jetting openings are substantially coplanar and are angularly disposed with respect to a longitudinal axis of the housing. Each of the jetting openings has a jetting nozzle disposed therein. In the preferred embodiment, the angle of the plane of the jetting openings is such that the plane may be positioned substantially perpendicular to an axis of least principal stress in a well formation adjacent to the well bore when the housing is disposed in the well bore. A method of fracturing a well is also disclosed and comprises the steps of positioning a jetting head in a well bore and directing a plurality of fluid jets from the jetting head at an angle with respect to the longitudinal axis of the well bore.

Abstract: A slow rotating mole apparatus for use in hydrablasting wellbores and pipelines. The apparatus generally consists of a motor section with a rotor rotatable in response to fluid flow through the motor section, a speed reducer section connected to the motor section such that an output speed of the speed reducer section is less than an output speed of the rotor, and a jetting section attached to the speed reducer section and rotated thereby at the speed reducer output speed. The speed reducer section and jetting section define a flow passage therethrough in communication with jetting ports in the jetting section so that the fluid pumped through the apparatus is jetted therefrom. The speed reducer section may include one or more gear reductions to achieve the desired rotational speed of the jetting section.

Abstract: Expandable casing portions are provided, such as casing slip joints or expansion joints, on opposite sides of a fracture initiation location to accommodate casing and formation movement during fracturing of a well. The fracture initiation location provided by forming openings through the well casing and then forming fan-shaped slots in the formation surrounding the casing. These fan-shaped slots circumscribe an angle about the axis of the casing substantially greater than the angle circumscribed by the opening itself through which the slot was formed. These techniques are particularly applicable to fracturing of horizontal wells, but are also useful on vertical wells. The expansion joints formed as tubular members having alternating inner and outer annular grooves. In another embodiment, the expansion joints formed by tubular members defining alternating inner and outer spiral grooves therein.

Abstract: Expandable casing portions are provided, such as casing slip joints or expansion joints, on opposite sides of a fracture initiation location to accommodate casing and formation movement during fracturing of a well. The fracture initiation location may be provided by forming openings through the well casing and then forming fan-shaped slots in the formation surrounding the casing. These slots may be formed by a hydraulic jet which is directed through the opening and then pivoted generally about the point of the opening. These fan-shaped slots circumscribe an angle about the axis of the casing substantially greater than the angle circumscribed by the opening itself through which the slot was formed. These techniques are particularly applicable to fracturing of horizontal wells, but are also useful on vertical wells.