Spontaneous potential log, commonly called the self potential log or SP log, is a passive measurement taken by oil industry well loggers to characterise rock formation properties. The …

The spontaneous potential log (SP) measures the natural or spontaneous potential difference (sometimes called self-potential) that exists between the borehole and the surface in the …

The spontaneous potential (SP) log was one of the earliest electric logs used in the petroleum industry, and has continued to play a significant role in well log interpretation. By far the largest …

2016年7月28日 · The spontaneous potential (SP) log was developed next and was presented along with resistivity logs. It is a measurement of the voltage difference between a movable …

2025年1月29日 · The SP log is typically scaled at 100 mV per log track. If the resistivities of the mud filtrate and formation water are similar, the SP deflections are small and the curve is …

2013年2月22日 · This document summarizes the spontaneous potential (SP) log. It discusses how SP works by measuring the natural potential difference between a downhole electrode …

Spontaneous potentials (SP) are usually caused by charge separation in clay or other minerals, due to presence of semi-permeable interface impeding the diffusion of ions through the pore …

2022年4月5日 · Water resistivity or R w, is a critical component of log analysis in calculating water saturation using the Archie equation. R w can be measured from a sample of formation water …

In this video, I explain how spontaneous potential (SP) log works. I also present a method to estimate Rw (resistivity of the formation water) from SP logs.

2018年9月7日 · SP log is one of the first tools used for formation evaluation. It measures the difference in potential or DC voltage between two points. One point is the electrode on the …