Downhole pressure measuring tool with a high sampling rate
First Claim
1. A dynamic monitoring system, comprising a single permanent downhole pressure gauge, means to transmit data from the downhole pressure gauge to the surface and a surface data acquisition unit wherein, on inducing a pressure change in a wellbore by an injection operation, the downhole pressure gauge records a pressure trace as data, the data is transmitted to the surface at a first sampling frequency, the data is stored in the surface data acquisition unit and fracture length is calculated from the stored data;
- wherein the pressure trace is a graph of downhole pressure against time showing a water pressure hammer wave with peaks and troughs, the pressure trace is treated with a fast Fourier Transform to provide a graph of amplitude against frequency with one or more amplitude peaks, the frequency of each amplitude peak correlating to a length of a fracture.
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Accused Products
Abstract
A dynamic monitoring system for dynamically monitoring injection operations on wells by determining the extent of fracturing using downhole pressure measurements. The system comprises a downhole pressure gauge, means to transmit data from the downhole pressure gauge to the surface and a surface data acquisition unit wherein, on inducing a pressure change in a wellbore by an injection operation, the downhole pressure gauge records a pressure trace as data, the data is transmitted to the surface at a first sampling frequency, the data is stored in the surface data acquisition unit and fracture length is calculated from the stored data to indicate extent of fracturing. Sampling frequencies are outside the known operating ranges.
25 Citations
20 Claims
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1. A dynamic monitoring system, comprising a single permanent downhole pressure gauge, means to transmit data from the downhole pressure gauge to the surface and a surface data acquisition unit wherein, on inducing a pressure change in a wellbore by an injection operation, the downhole pressure gauge records a pressure trace as data, the data is transmitted to the surface at a first sampling frequency, the data is stored in the surface data acquisition unit and fracture length is calculated from the stored data;
- wherein the pressure trace is a graph of downhole pressure against time showing a water pressure hammer wave with peaks and troughs, the pressure trace is treated with a fast Fourier Transform to provide a graph of amplitude against frequency with one or more amplitude peaks, the frequency of each amplitude peak correlating to a length of a fracture.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
Specification