US 4,392,377 AGranted

Early gas detection system for a drill stem test

AssigneeGearhart Industries, Inc.

InventorE. Edward Rankin

Life of this patent

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Abstract

A method for testing earth formations informs the operator of the density of the formation fluid being produced before it reaches the surface. In the method, a bypass sub is secured to the drill string. The bypass sub has a bore for receiving a wireline tool that has sensing instruments. The wireline tool also has arms that will shift a sleeve to open and close the bypass sub. The wireline tool has a density measuring device for measuring the density of the formation fluid and providing a concurrent surface indication. A reversing valve is located above the bypass sub and is of a type that provides a port for reverse circulation while the wireline tool is still downhole. Preferably, the reversing valve is shifted by the wireline tool to the open position.

Claims9

Dependent claims

In a method for providing concurrent surface indication of earth formation characteristics during drill stem testing, the method including the steps of running in on a drill string a releasable packer and a bypass sub having a bore for sealingly receiving a wireline tool and a bypass passage means permitting formation fluid flow around the wireline tool, then selectively opening and closing the bypass passage means with the wireline tool sealed in the bore and the packer set to selectively shut in and allow formation fluid flow to the surface while concurrently providing to the surface through the wireline formation flowing and shut in characteristics sensed by the wireline tool, the improvement comprising:

providing for the wireline tool, sensing means for sensing the gas content of the formation fluid and providing a concurrent indication to the surface;
providing a reversing valve means for communicating a well annulus with the interior of the drill string while the wireline instrument is located downhole;
stopping the flow of formation fluid should the sensing means indicate the possibility of a gas flow rate above a selected safe minimum;
then
reversing circulating annulus fluid from the annulus down through the reversing valve means and up the drill string to remove formation fluid from the drill string;
then
removing the wireline tool.

4 more elements

In a method for providing concurrent surface indication of earth formation characteristics during drill stem testing, the method including the steps of running in on a drill string a releasable packer and a bypass sub having a bore for sealingly receiving a wireline tool and a bypass passage means for preventing formation fluid flow around the wireline tool, then selectively opening and closing the bypass passage means with the wireline tool sealed in the bore and the packer set to selectively shut in and allow formation fluid to flow to the surface while concurrently providing to the surface through the wireline formation flowing and shut in characteristics sensed by the wireline tool, the improvement comprising;

providing the wireline tool with density means for sensing the density of the formation fluid and providing a concurrent indication to the surface;
providing a reversing valve means above the bypass passage means that is actuable by the wireline tool for communicating a well annulus with the interior of the drill string;
withdrawing the wireline tool from engagement with the bypass passage means and opening the reversing valve means with the wireline tool should the density means indicate the possibility of a gas flow rate above a selected safe minimum, the valve means being opened by extending a dog from the wireline tool into engagement with a stationary portion of the reversing valve means, and extending an arm from the wireline tool for engaging a sliding sleeve of the reversing valve means, then moving the arm to slide the sleeve;
reverse circulating annulus fluid from the annulus through the reversing valve means and up the drill string while maintaining the dog in engagement with the reversing valve means;
then
disengaging the arm and dog from the reversing valve means and withdrawing the wireline tool to the surface.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 06/305,947Filed 28 Sep 1981
Granted: 12 Jul 1983
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

E21B 34/14
In wells: operated by movement of tools, e.g. sleeve valves operated by pistons or wire line tools
E21B 47/06
Survey of boreholes or wells: measuring temperature or pressure
E21B 47/11
Locating fluid leaks, intrusions or movements: using tracers; using radioactivity
E21B 47/111
Using tracers; using radioactivity: using radioactivity

Family

No related US applications are recorded in the indexed filing history.

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