Abstract: The invention relates to a method of obtaining a developed two-dimensional image of the wall of a borehole. The method comprises the steps consisting in: measuring a primary physical magnitude in said borehole as a function both of depth and of azimuth; measuring a secondary physical magnitude in said borehole as a function of depth; establishing a relationship (ƒ) between said primary physical magnitude and said secondary physical magnitude; and deducing from said relationship values for said secondary physical magnitude as a function both of depth and of azimuth, which method makes it possible to reconstruct a two-dimensional image developed over the wall of a borehole concerning a secondary physical magnitude which is measured in said borehole as a function of depth only. The invention is particularly applicable to density imaging.

Abstract: Sensors are permanently placed in the ground near observation and injection wells in order to passively and continuously monitor the status of seawater advance toward fresh water aquifers near coastal cities as well as the status of fresh water injected into the injection wells. Such sensor devices are installed in the ground and electrically connected to surface acquisition equipment that would, without human intervention, transmit acquired data to a centralized facility for processing and interpretation. Various types of sensors can be used: the sensors used for general reservoir monitoring and/or the sensors used for leak detection, soil heating, and temperature mapping. Alternatively, a special type of sensor can be designed and provided for the purpose of monitoring the status of seawater advance toward fresh water aquifers.

Abstract: Sensors are permanently placed in the ground near observation and injection wells in order to passively and continuously monitor the status of seawater advance toward fresh water aquifers near coastal cities as well as the status of fresh water injected into the injection wells. Such sensor devices are installed in the ground and electrically connected to surface acquisition equipment that would, without human intervention, transmit acquired data to a centralized facility for processing and interpretation. Various types of sensors can be used: the sensors used for general reservoir monitoring and/or the sensors used for leak detection, soil heating, and temperature mapping. Alternatively, a special type of sensor can be designed and provided for the purpose of monitoring the status of seawater advance toward fresh water aquifers.