I3 Energy PLC (LON:I3E) said a pilot well at its Liberator field will did not reach its target area and so will be plugged and abandoned.
The oil and gas firm said the target upper Captain sand area had not been penetrated by the well and that more well data was needed to interpret and locate the key reservoir.
As a result, I3 said preparations were being made to obtain a vertical seismic profile in the well and also run a shear wave sonic log, after which 13/23c-9 would be plugged and abandoned.
The data would then be used to recalibrate and update the existing seismic models so that further drilling in the area would be better suited to locate a future development well.
The shares were down 40.4% at 33.3p in late-morning trading on Tuesday.