A tool for performing a downhole function in a horizontal or highly deviated well has a downhole structure with a longitudinal axis and constructed to turn about the axis in response to a moment applied about the axis. The structure includes at least one ballast chamber containing a flowable inert ballast material, such that the gravitational center of the material-containing chamber is effectively offset from the longitudinal axis of the structure to enable the chamber to contribute to gravitational orientation of the tool within the well to a desired position. In another configuration, the structure is rotatable within a housing and supported by bearings. The chamber is preferably filled with tungsten or depleted uranium powder for maximum density. A swivel for use with the tool, capable of passing both hydraulic pressure and detonation waves, decreases the overall length of the rotating part of the tool string. The method of using an offset ballast to desirably orient a tool in a horizontal or highly deviated well is also disclosed.
An internally oriented perforating apparatus and associated method of perforating provide increased reliability in orienting perforating charges to shoot in desired directions in a well. In a described example, a perforating gun includes a tubular gun carrier, multiple perforating charges, multiple charge mounting structures and multiple rotating supports. The rotating supports are attached between the charge mounting structures, or at least between the perforating charges.
One embodiment of the present invention discloses a shot indication device that indicates the orientation of a downhole tool that is inside of a wellbore at a particular time. The shot indication device can also be used to determine the orientation of a perforating gun with shaped charges at the instant the shaped charges are detonated. The shot indication device is comprised of an indicator housing secured within the downhole tool. Formed within the indicator housing is an annulus whose axis is parallel to the axis of the downhole tool. Disposed inside of the annulus is an indicator element that freely moves about the circumference of the annulus.
A method and apparatus for use in a wellbore includes explosive components, a housing containing the explosive components, and at least one protection barrier mounted on the housing to reduce transmissibility of an external force load to the housing. The explosive components array include shaped charges and detonating cords for use in perforating guns.
A weight spacer apparatus has a carrier which is tubular in shape and a spacer tube which is also tubular in shape for insertion into the carrier. The weight spacer apparatus also has a plurality of weight bars which may be inserted into the spacer tube after the spacer tube is inserted into the carrier and which are also removable from the spacer tube. In one embodiment, a weight tray is inserted into the spacer tube for receiving the weight bars, and the weight tray may be fabricated from half-round tubing with a welded plate to cover the diametric opening. In another embodiment, a center plate is attached inside the spacer tube along the length of the spacer tube to divide the spacer tube into first and second compartments.
The present invention provides an apparatus and method of orienting perforating gun strings conveyed on a tool string. One embodiment of the present invention provides an orienting weight provided in a portion of the perforating device, such as the shaped charge, the loading tube or the gun housing. An adapter is provided intermediate the tool string that facilitates conveyance of the gun string downhole. Additionally, the adapter enables the gun string to rotate independent of the tool string.
