Downhole Telemetry Data Compression Using Reference Shape Imposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current data compression methods for mud pulse telemetry in drilling operations are inefficient for large delta values and can cause delays, limiting the effective data rate and bandwidth for transmitting real-time formation data from downhole tools to the surface.
Innovation Solution
The implementation of an image imposition scheme that selects a pre-determined reference shape to minimize the delta values between initial and actual sensor data, reducing the number of bits required for transmission and optimizing the telemetry data rate by transmitting delta values and the reference shape to the processor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If delta compression methods are used to transmit formation data from downhole tools, then data transmission bandwidth is reduced, but transmission delay increases and large delta values cannot be compressed effectively
Solution Approach 1:
The system performs preliminary action by transmitting the reference shape data before the actual sensor data. The reference shape is sent first, then the delta values are transmitted. This preliminary transmission of the reference shape allows the receiver to have the necessary context for properly interpreting the delta values, effectively reducing transmission delay while maintaining compression benefits.
Solution Approach 2:
The data transmission is segmented into two distinct parts: first the reference shape is transmitted, then the delta values are transmitted. This segmentation allows each part to be optimized independently - the reference shape can be transmitted with appropriate formatting, and the delta values can be compressed effectively, addressing both bandwidth and delay concerns.
2Productivity
If existing compression methods are used for mud pulse telemetry, then data rate is limited, but real-time data transmission capability is insufficient for controlling drilling tools and building dense geological models
Solution Approach 1:
The system changes the parameter of data representation by using delta values instead of absolute values for transmission. This parameter change allows the system to maintain real-time data transmission capability while reducing the data rate requirement, as delta values are typically smaller than absolute formation data values.
3Measurement precision
If raw image data is transmitted without compression, then data quality is maintained, but telemetry hardware data rate demand increases and maintenance service interval is reduced
Solution Approach 1:
The system uses feedback by transmitting delta values that represent changes from the reference shape. This feedback mechanism allows the receiver to reconstruct the actual shape data by combining the reference shape with the delta values, maintaining data quality while significantly reducing the data rate demand on telemetry hardware.
Data Source
AI summary
A method includes obtaining, by a downhole tool, a first shape of sensor data representing one or more characteristics of a wellbore, comparing, by the downhole tool, the first shape with a set of pre-determined reference shapes stored in a downhole memory to select a pre-determined reference shape that can be imposed on the first shape, calculating one or more delta values between the first shape and the selected pre-determined reference shape, and transmitting, by the downhole tool, the pre-determined reference shape and the delta values to a processor at a surface of the wellbore.