What are the best practices and standards for DPT measurement in horizontal and directional wells?

1 DPT sensors and tools

The most common types of DPT sensors and tools used in horizontal and directional wells are wireline, memory, and permanent gauges. Wireline gauges are run on a cable and can be moved along the wellbore to measure DPT at different locations. Memory gauges are battery-powered devices that store DPT data in their internal memory and are retrieved after the operation. Permanent gauges are installed at fixed locations in the wellbore or near the reservoir and transmit DPT data to the surface via electrical or optical cables.

2 DPT measurement objectives

The objectives of DPT measurement in horizontal and directional wells may differ according to the well type, phase, and purpose. For example, it can be used to determine the reservoir pressure and temperature profiles along the wellbore and across the reservoir boundaries, as well as to monitor the wellbore stability and integrity during drilling, completion, and production. Additionally, it can be used to evaluate the well performance and productivity under different flow rates and conditions, as well as identify and diagnose any anomalies or issues in the well or reservoir such as leaks, fractures, or water breakthrough.

3 DPT measurement planning

Achieving the desired objectives of DPT measurement requires a proper planning process. This includes selecting the right DPT sensors and tools based on the well geometry, environment, and operational constraints. Additionally, you must determine the optimal locations and intervals for DPT measurement along the wellbore and in the reservoir. Furthermore, you should estimate the expected DPT ranges and uncertainties based on the well and reservoir models and data. Lastly, you should define the DPT measurement procedures, protocols, and quality control standards.

4 DPT measurement execution

The execution of DPT measurement in horizontal and directional wells should adhere to established procedures, protocols, and standards to guarantee the accuracy and reliability of the data. Some key factors to bear in mind during the execution include calibrating and verifying the DPT sensors and tools before and after each run or installation, deploying and retrieving the sensors and tools properly in the wellbore while avoiding any damage, interference, or contamination, sending, storing, and backing up the DPT data securely from the sensors and tools to either the surface or remote systems, as well as monitoring, analyzing, and interpreting the DPT data in real-time or periodically to identify and address any problems or anomalies.

5 DPT measurement challenges

Despite the advances in technology and methodology, DPT measurement in horizontal and directional wells still faces numerous challenges that can affect data quality and reliability. High pressure and temperature conditions can exceed operational limits or degrade the performance of DPT sensors and tools. Multiphase flow and fluid properties can cause fluctuations, noise, or errors in the DPT data. Furthermore, wellbore geometry and trajectory can create difficulties or risks in deploying, retrieving, or positioning the DPT sensors and tools. Additionally, interference or compatibility issues between the DPT sensors and tools and other downhole equipment or systems, such as logging tools, packers, valves, or pumps, can also occur.

6 DPT measurement best practices

To ensure successful DPT measurements in horizontal and directional wells, it is important to use robust and reliable DPT sensors and tools that are designed and tested for the specific well conditions and applications. Additionally, corrections and adjustments to the DPT data should be made based on fluid properties, wellbore effects, and sensor characteristics. Furthermore, it is beneficial to validate and cross-check the DPT data with other sources of information, such as well logs, tests, or models. Finally, industry standards and guidelines for DPT measurement, such as API RP 11S5, ISO 10431, or NACE MR0175 should be followed.