ElectroSpin measures the resistivity indices of core samples in just two days!
A project presented by Régis Brugidou, Quentin Danielczick, Pierre Faurissoux, Benjamin Nicot and Ghislain Pujol
In a world first, the solution ElectroSpin makes it possible to measurer a reservoir’s hydrocarbon and water content in just two days! This saves considerable time, makes handling easier, improves the safety of laboratory measurements and slashes costs while maintaining a high level of reliability.
On point in resistivity!
A reservoir’s hydrocarbon content is a key petrophysical measurement since it is used to estimate the volume of gas or petroleum on site, and therefore the reservoir’s potential. Until recently, it was measured using three conventional techniques: extracting fluids from a sample of rocks taken from the well, studying the resistivity indices of these cores using electric logs (RI) and analyzing capillary pressure curves (Pc). The RI and Pc methods are quite costly and time-consuming, taking nearly 10 months. Moreover, they measure only the average properties of a given sample.
In 2018, TotalEnergies rolled out a new exclusive method, UltraFast PcRI, which brought this time down to just one month. This major advancement is based on the simultaneous use of saturation and nuclear magnetic resonance (NMR) resistivity imaging.
Three major innovations in laboratory rock core measurements
Today, the same TotalEnergies Geosciences team is taking saturation calculation even further. Its ElectroSpin method reduces the time required to two days thanks to a new rock resistivity index evaluation system:
- Electrical measurements of the resistivity imaging are integrated inside a rotating centrifuge.
- The data is then transmitted outside the centrifuge for real-time processing.
- A digital inversion with automated interpretations replaces conventional saturation measurement, which was a long and costly process.
This combination of a “smart” centrifuge, a wireless technology and digital processing opens the way to an all-new approach. The centrifuging creates a water saturation variation in the sample. The resulting resistivity variations are measured remotely with a wireless method and inversed into usable Pc and RI data. The resistivity data collection carried out in the centrifuge is sufficient for determining the saturations with good consistency.
The new ElectroSpin method simultaneously determines the capillary pressure curve and the resistivity parameters necessary for an interpretation of the resistivity logs.
IRRESISTIBLE reliability and performance!
To transmit the data outside the centrifuge, three advancements have been decisive: the fine-tuning of a multiple-electrode device connected wirelessly to the stator (RFID), the optimization of the electrode spacing to achieve the best spatial resolution of the resistivity measurements, and good contact between the rock sample and these electrodes.
A unique patented technology, ElectroSpin yields highly reliable results, with:
- Considerable time saved.
- A significant reduction in the number of handling hours.
- Greater safety, with less exposure to toxic chemical products.
- A significant reduction in cost.
- A technology that’s easy to reproduce, based on a specified design, equipment that is manufactured and existing software.