Abstract: A process for isolating one or more segments of a gravel packed well from other segments to treat the isolated segments and easily re-establish flow from the other segments after the treatment is described. The treatment includes techniques for enhancing or permanently blocking production from the isolated segment. The process includes the installation of a removable sealing element and a permeability poison that forms a fluid seal to prevent longitudinal fluid flow along the annular production space outside the tubular production pipe. With wireline or other low-cost wellbore workover systems, access is re-engaged with the secluded formation including removal of plugs and fluid seals within the tubular production pipe.

Abstract: A process for sealing off one or more segments of a gravel packed well to reduce the production of undesirable fluids. The process includes the installation of a removable plug and the installation of a removable sealant at a location in the gravel packing to separate portions of the formation that produce desirable products from portions that produce less desirable products. A flow poison is then squeezed into the portion of the formation that produces less desirable products. With wireline or other low-cost wellbore workover systems, access is re-engaged with the preferred formation including removal of plugs and sealants without mechanical drilling. The process allows increased production of preferred fluids by preventing less or non preferred fluids from displacing the preferred fluids and also reduces lifting costs that would otherwise be expended for lifting and expenses related to separating and disposing of non preferred fluids.

Abstract: This invention relates to a process for isolating one or more segments of a gravel packed well from other segments to treat the isolated segments and easily re-establish flow from the other segments after the treatment. The treatment includes techniques for enhancing or permanently blocking production from the isolated segment. The process includes the installation of a removable plug and a permeability poison that forms a fluid seal to prevent longitudinal fluid flow along the annular production space outside the tubular production pipe. With wireline or other low-cost wellbore workover systems, access is re-engaged with the secluded formation including removal of plugs and fluid seals within the tubular production pipe. The inventive process allows enhanced recovery of fluids by focusing treatments on problem areas without harming productive segments of the well.

Abstract: A method and composition for isolating a selected subterranean formation in a subterranean formation having a gravel pack over a plurality of producing zones.

Abstract: Core samples are obtained through production wells by inserting a milling tool through the production tubing string on the distal end of coilable tubing to mill out a window in the well casing. The milling tool is deflected by a whipstock set in the casing at a predetermined point and encased in cement which, upon setting, is bored to form a pilot bore for the milling tool. A fluid-motor-driven core barrel is provided on the end of the tubing after the milling operation is complete and core drilling is carried out in an underbalanced condition by reducing wellbore pressure through a gas lift so as to minimize core invasion by wellbore fluids including spent milling motor and core drilling motor fluids.

Abstract: An automatic timed shut-in valve for pressure transient testing of a well and the like includes a body member adapted for connection to a locking device for locating the valve at a predetermined point in a tubing string. The valve includes a clock timer and an actuator which is operable to close the valve at a predetermined time after insertion of the valve in the tubing string. Various operations may be carried out including automatic times shut-in of a well or pressure transient testing by recording at least one of pressure and temperature in the well in timed relationship to actuation of the valve so that wellbore and formation conditions can be measured upon shut-in of the well.