2D Well Testing with Smart Plug Sensor

Abstract

An apparatus for characterising the permeability of a formation surrounding a wellbore, comprising:

• • a drillstem test (DST) tool comprising, a packer for isolating a zone of the wellbore, a valve for controlling fluid into and out of the zone via the drill string of the tool and, a pressure gauge for detecting the pressure in the zone;
  • wherein the apparatus further comprises an array of at least two antennas arranged on the tool above the packer such that when in use each antenna of the array aligns with a corresponding pressure sensor placed in the formation to obtain pressure measurements and therefore allow horizontal and vertical permeability to be determined.

Description

TECHNICAL FIELD[0001]This invention relates to an apparatus for characterising the permeability of a formation surrounding a borehole well. In particular permeability is determined by measuring the formation and borehole pressure in oil, gas or similar wells.BACKGROUND ART[0002]Once a well has been drilled, a well test is usually performed to characterise the formation surrounding the borehole. Properties such as skin, permeability, porosity of a reservoir, and production capacity are some the properties used to characterise the formations. Knowing how fluids flow through a reservoir is important for managing hydrocarbons reserves. Fluid flow is governed by the permeability of the formations.[0003]A conventional well test can determine formation properties from pressure measurements obtained by a drillstem test (DST) tool as shown in FIG. 1. In a conventional well test operation transient well test conditions are applied to the well and the pressure below a tester valve is measured....

AI Technical Summary

Problems solved by technology

However often formations are not homogenous in quality and will have layering features.

In such cases the results obtained in terms of reservoir properties from testing the whole thickness, h, is representative of some average of the individual layer permeability which is not really useful to a reservoir engineer for assessing the potential of the well or the field under evaluation.

Such a test only provides a one dimensional characterization that is only valid for perfectly homogenous medium.

Because most formations are not homogenous but rather show a layering structure, a single pressure measurement does not sufficiently characterize each individual layer component.

In addition it is not possible to obtain a characterization of the vertical permeability from the results of a single probe.

However these methods only result in a single pressure measurement and do not simultaneously measure the pressure at different depths of the borehole and therefore are not sufficient to characterise each individual layer component of a formation in a single test.

Images