Photomultiplier Tubes for Oil Well Logging

Source: Hamamatsu Corporation

The oil and gas industry uses well logging techniques in order to obtain information on the properties of the rocks and earth that they’re drilling into. This can be conducted through visually inspecting samples brought to the surface, or by using instrumentation lowered directly into the hole. This is also known as capturing geophysical logs. There are several types of instrumentation that can be used in geophysical logging applications for the oil and gas industry. This page will provide an overview of a photomultiplier tube’s role in this type of application.

Photomultiplier tubes (PMTs) are used to detect ultraviolet (UV), visible (VIS), and near-infrared (NIR) ranges of light. They exhibit high sensitivity and high response time, making them well suited for exploratory drilling for shale gas and oil reserves. However, since geophysical logging can take place during the actual drilling phase of a well’s history, they need to exhibit durability, particularly where temperature resistance and the ability to handle high vibration are concerned.

Oil well logging is ultimately conducted in order to locate an oil deposit and get a better understanding of its size. Photomultiplier tubes can be used as detectors for density well logging using radiation, neutron well logging, and natural gamma-ray-spectrum well logging. In these different types of oil well loggings, a probe containing a neutron or gamma ray source is lowered into a well as it’s being drilled. (This is why PMTs with high tolerance to shock, vibration, and severe temperatures are necessary.) The radiation or the neutrons that are scattered by the rock surrounding the well are then detected by the PMT. The amount of scattered radiation detected indicates the density of the rock surrounding the oil well. Scattered neutrons tell us the porosity of the rock, which determines if the oil can actually be removed.

Hamamatsu Photonics recently developed a new photomultiplier tube that offers 1.7 times the durability of previously manufactured PMTs designed for oil and gas exploratory drilling. The R8874-01 is a high-temperature head-on PMT designed for manufacturers of well logging equipment. While the R8874-01 is the most recent entry into this series, Hamamatsu has a robust line of other ruggedized high temperature photomultiplier tubes for oil well logging applications. Download the catalog for more information.

Visit Hamamatsu’ website for more information.