Other

Conoco Inc.

Maurer Engineering Gmbh

Donald W Dareing

Edward T Wood

Robert F Snyder

William C Larson

William A Rehm

A method, and apparatus to practice the method, to complete multiple (triple) branch wells using separate drill and casing templates. Principally this invention finds its greatest utility in the in situ leach mining of deep lying ore bodies. Initially, a generally vertical main hole is drilled in the earth and cased. The particular casing used has an internal indexing dog and specific areas which act as windows from which some of the branch wells are to be drilled. To form the individual branch wells, each window is sequentially drilled out by a drilling assembly which is oriented by a movable drilling template. The template is fixed with respect to the casing for each branch drilling by engaging the indexing dog. After each window and branch well is drilled, the drilling assembly and drilling template are retrieved to the surface and repositioned with respect to each other to provide for the next branch drilling. A whipstock assembly is used in connection with the drilling template and indexing dog to positively locate each branch well. After all branch wells are drilled, the whipstock assembly is retrieved. Next a triple tubing guide or template, which can engage the same indexing dog, is used to simultaneously position branch casings in each of the previously drilled branch holes. A tubing hanger is used to position and hold these casings within the main casing. Cement baskets are attached to the shoe (end) of each branch casing and all casings are cemented in place. Lastly, the branch wells may be perforated, unless this has been done in the casing production process, and the well is then ready for production.

Triple branch completion with separate drilling and completion templates

A method and the necessary equipment to form horizontal cased and perforated drainholes for an underground, in situ leach mining operation. After a vertical hole has been formed and cased in the earth, horizontal drainholes are to be drilled from below its casing. The depth and thickness of the ore body which is to be recovered is determined. Following this, the proper whipstock orientation is computed and the horizontal drainhole is whipstocked and drilled from above the ore bed into it. A flexible casing, such as Coflexip pipe, is used to case the drainholes. Perforations or slots are provided for in these casings before they are put in the earth. A special retrievable cement plug, basket, and one-way valve are used to control and direct the flow of cement to the volume between the outside of the juncture at the casings.

Method and apparatus to complete horizontal drain holes

A method of drilling and completing multiple branch wells extending from a main generally vertical hole. This invention finds its primary applicability in in situ leach mining of deep (500 to several thousand feet) lying ore bodies such as uranium, copper, etc. Initially, the main generally vertical hole is drilled, cased, and cemented. Whipstock drilling guides are placed to extend downwardly and outwardly from the bottom of the casing for this hole and cemented in place. These guides are the same in number as the branch holes to be drilled. In addition, the well bore casing contains an indexing dog just above the whipstock drilling guide. The actual drilling of the branch wells is accomplished with a floating index collar and a drill bit assembly which runs therewith. The indexing dog is fixed in the main hole and engages the indexing collar so that the drill bit is oriented to drill into one of the whipstock drilling guides. After a particular branchis drilled, the collar and bit are retrieved from the main hole. The bit is then placed in another hole of the collar and the combination reinserted in the main hole where it again engages the indexing dog and allows drilling of another branch well. After all branch wells are drilled, they are cased with a flexible casing, like fiberglass, cemented and selectively perforated. If the well is a liquid recovery well, a pump is placed at the bottom of the main vertical hole casing near where it joins the branch wells.

Multiple branch completion with common drilling and casing template

A multiple branch well for use with in situ leach mining of deep lying ore bodies. The branch wells may be formed by a method disclosed in a related invention. Each well may have two branches one of which is a producer well and one an injector well. Internally of the main casing from which the two branch casings extend are--from the lower end up--a packer unit, a tubing hanger, and a wireline retrievable hydraulically generated pump. The packer and tubing hanger serve their conventional function of, respectively, blocking the flow of leach fluids and holding the branch tubular casing in place within the main casing. The hydraulic pump joins the tubular casings to maintain a constant ratio of produced fluid to injected fluid. This pump is operated by a pressurized fluid source. Since it is retrievable and hydraulically operated, the pump can be brought to the surface for any repairs or maintenance and it requires less surface plumbing with no down hole electrical power.

Multiple branch well containing one producer and one injector well

A downhole riser assembly includes a tubular casing embedded in the ocean floor, said casing having a constant internal diameter and an upper end extending above said ocean floor. A tubular riser pipe is disposed in the casing and has an upper end connected to a floating vessel which may be a tension leg platform. The casing and riser are rigidly connected at a considerable distance below the ocean floor, said distance being on the order of 100 feet. When the floating structure is laterally displaced from a position directly above the casing, the riser pipe contacts the upper end of the casing. This contact limits the lateral deflection of the riser at the ocean floor and thereby limits the stresses in the riser. The distance between the upper end of the casing and the downhole connection between the casing and the riser, and the diameter of the casing are such that the riser has a rotational stiffness, adjacent the upper end of the casing, within a range such that both a maximum design maximum stress and a maximum design bottom slope of said riser are not exceeded when said riser is subjected to maximum design loading conditions. An alternative embodiment of the present invention provides a lateral support means for connecting the riser and the casing adjacent the upper end of the casing for restricting lateral movement of the riser.

Downhole riser assembly

A method and apparatus are disclosed for connecting a flowline having a major portion adapted to lie along the floor of a body of water to an offshore connection point. The method and apparatus are designed to compensate for the difficulty encountered in laying and maintaining an underwater flowline in a body of water having a substantial current running in substantially a single direction. The flowline is fed from a flowing support and drawn by a cable into an alignment funnel. Means are provided to bow the leading flowline in a lateral non-vertical direction by a predetermined amount such that the end of the leading flowline may enter the alignment funnel without any lateral or angular displacement. The bowing may be done at the surface prior to submersion of the flowline or may be done after the flowline is submerged. Several means for bowing the flowline are disclosed.

Growing community of inventors

Houston, TX, United States of America

Donald W Dareing