Formation Pressure Testing with Hybrid Power and Low-Noise Buildup
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing formation pressure testing during drilling operations face challenges in achieving accurate measurements due to noise interference from mud pumps and limited power supply from batteries, leading to potential tool sticking and inefficient data transmission.
Innovation Solution
A hybrid power system combining a mud turbine generator and batteries powers the formation testing tool, allowing switching between power sources during the test to minimize noise and ensure accurate measurements, including a drawdown phase with generator power and a buildup phase with battery power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If mud pumps are engaged to provide power and prevent sticking, then productivity and reliability improve, but measurement precision deteriorates due to noise
Solution Approach 1:
The formation pressure test is divided into two distinct phases: a drawdown phase where mud pumps are engaged to provide power and prevent sticking, and a buildup phase where mud pumps are disengaged to enable accurate measurement. This temporal segmentation allows the system to optimize for different objectives in different phases.
Solution Approach 2:
The system dynamically switches between two operational modes by controlling the mud pump engagement state. The pump is engaged during the drawdown phase and disengaged during the buildup phase, allowing the system to adapt its configuration based on the current test phase requirements.
2Measurement precision
If mud flow is stopped to measure formation pressure accurately, then measurement precision improves, but reliability deteriorates due to tool sticking risk
Solution Approach 1:
The test procedure is segmented into drawdown and buildup phases, where the mud pump is engaged during drawdown to maintain fluid flow and prevent sticking, then disengaged during buildup to enable accurate pressure measurement. This segmentation allows the system to address both reliability and measurement precision requirements at different times.
Solution Approach 2:
The drawdown phase serves as a preliminary action that establishes proper tool positioning and seal contact before the critical buildup measurement phase. By performing the drawdown with pump engagement first, the system ensures the tool is properly seated and sealed before stopping the pump for measurement.
3Measurement precision
If battery power is used to avoid pump noise, then measurement precision improves, but power capability is insufficient for high drawdown rates
Solution Approach 1:
The system merges two power sources: the mud pump hydraulic power (available during drawdown phase) and battery electrical power (available during buildup phase). This combined power system allows the drawdown phase to achieve high power output for accurate measurement while the buildup phase uses battery power to minimize noise.
Solution Approach 2:
The formation testing tool is designed to operate with multiple power sources serving different functions: the mud pump provides hydraulic power and fluid flow during drawdown, while the battery provides electrical power during buildup. This multi-functionality allows the system to overcome the limitations of either power source alone.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables high-quality formation pressure tests with minimal pumps-off time, improving measurement accuracy and reducing the risk of tool sticking, while allowing real-time data transmission and efficient power supply.
Implementation Method 1
power from a generator may be necessary to provide sufficient power for the high drawdown rates
Implementation Method 2
mud flow allows downhole generators or turbines to remain active and supply power to any downhole tools
Implementation Method 3
the power needed to operate the formation tester must be supplied by other means, such as batteries
Implementation Method 4
mud flow also allows for mud pulse telemetry where a downhole tool restricts the mud flow to create pressure waves that may be detected at the surface
Data Source
AI summary
Methods and systems for performing a formation pressure test include inserting a bottom hole assembly (“BHA”) into a wellbore. The BHA includes a drill bit and a formation testing tool with a battery. An initial formation pressure test is performed. At least a portion of a planned formation pressure test is performed powering the formation testing tool with the battery. The method also includes determining, using a processor, at least one characteristic of the formation based on results of the initial formation pressure test and the planned formation pressure test.