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Time Lapse Logging in the Same BHA Using Logging While Drilling

IP.com Disclosure Number: IPCOM000030737D
Publication Date: 2004-Aug-24
Document File: 1 page(s) / 25K

Publishing Venue

The IP.com Prior Art Database

Abstract

Invention Summary: Time Lapse Logging in the Same BHA Using Logging While Drilling Time Lapse Logging in the Same BHA Using Logging While Drilling can be accomplished by inserting another like sensor device in the Bottom Hole Assembly (BHA). Normally time lapse is accomplished with another descent in the well-bore and is accomplished using logging while drilling or wireline acquisition methods followed by another descent with either a logging while drilling or wireline instrument. In our invention, another descent in not required, but rather a like instrument(s) or sensor(s) is put in the BHA at some spacing behind the like instrument(s) or sensor(s) that is closest to the bit. Since drilling involves time versus the depth of sensor or instrument position, the acquisition of the information from the instrument(s) or sensor(s) spaced behind the one closest to the bit will provide similar information as the measurement(s) nearer the bit, but the measurement(s) will be displaced in time. The information and measurement(s) acquired displaced in time will be subject to a variety of changes in the wellbore and/or subsurface rock and fluids as a result of the action of cutting the rock and fluids from the wellbore entering the rock or fluids from the rock entering the wellbore, as well as disturbance of the rock itself near the wellbore through the process of drilling. Potential applications for the use of time lapse logging in the same string of instruments on one descent in the wellbore include evaluation of swelling formations, release of stress evaluation around the wellbore, invasion of borehole fluids into the formation, detection or inference of potential hazardous occurrences of gases and fluids entering the wellbore from the information, inference of permeability as a result of fluid invasion or influx, inference of formation pressures greater or less than the pressure in the wellbore, and detection of interval time changes as a result of shale hydration.

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Invention Summary:  Time Lapse Logging in the Same BHA Using Logging While Drilling

Time Lapse Logging in the Same BHA Using Logging While Drilling can be accomplished by inserting another like sensor device in the Bottom Hole Assembly (BHA).

Normally time lapse is accomplished with another descent in the well-bore and is accomplished using logging while drilling or wireline acquisition methods followed by another descent with either a logging while drilling or wireline instrument.

In our invention, another descent in not required, but rather a like instrument(s) or sensor(s) is put in the BHA at some spacing behind the like instrument(s) or sensor(s) that is closest to the bit.

Since drilling involves time versus the depth of sensor or instrument position, the acquisition of the information from the instrument(s) or sensor(s) spaced behind the one closest to the bit will provide similar information as the measurement(s) nearer the bit, but the measurement(s) will be displaced in time.

The information and measurement(s) acquired displaced in time will be subject to a variety of changes in the wellbore and/or subsurface rock and fluids as a result of the action of cutting the rock and fluids from the wellbore entering the rock or fluids from the rock entering the wellbore, as well as disturbance of the rock itself near the wellbore through the process of drilling.

Potential applications for the use of time lapse logging in the same string of instruments on one descent in the...