Abstract: Apparatus and method for noninvasive surface or remote monitoring of activity downhole in a cased bore hole wherein vibrations transmitted through the casing are detected by a vibration transducer coupled to the casing to obtain information about the activity occurring downhole in the cased bore hole. In one embodiment, an acoustic wave or vibration detector is coupled to the wellhead of an existing well or wells. The detector detects the acoustic waves or vibrations transmitted through the existing well that are caused by the drilling of the new well in close proximity to the existing well casing. When the monitored vibrations meet a predeterminedd criteria indicating a closely approaching drill bit or the drill bit striking the casing of an existing well, an alarm signal is produced to warn of the close approach or impact so that appropriate responsive action may be taken.

Abstract: A method for selectively producing oil from a reservoir containing both oil and gas. A lateral or horizontal wellbore is drilled within the reservoir below the gas-oil interface, and the wellbore has an inverted producing interval that is upwardly inclining towards the tail of the well. The inverted wellbore is drilled and completed in order to improve reservoir drainage by causing gas breakthrough to occur first at the far end of the upwardly inclining producing interval. A fluid restrictor is activated to restrict gas production from this breakthrough area and to permit oil production above the restrictor.

Abstract: A method for selectively producing oil from a reservoir containing both oil and gas. A lateral or horizontal wellbore is drilled within the reservoir below the gas-oil interface, and the wellbore has an inverted producing interval that is upwardly inclining toward the tail of the well. The inverted wellbore is drilled and completed in order to improve reservoir drainage by causing gas breakthrough to occur first at the far end of the upwardly inclining producing interval. A fluid restrictor is activated to restrict gas production from this breakthrough area and to permit oil production above the restrictor.

Abstract: A method for completing a well to provide an uncemented lower casing and an upper cemented casing. The lower casing and upper casing are connected at a swivel joint so that only the upper casing is rotated while cementing. Inflatable packers and a plug are positioned at the lower casing to prevent entry of cement, while a port collar allows cement to flow into the annulus surrounding the upper casing.The invention is particularly useful when setting long lengths of casing and when completing highly deviated or horizontal wellbores. The method also allows an existing conventionally-completed well to be re-drilled and completed as a highly-deviated or horizontal well.