[en] This paper described a method for analyzing the efficiency of exploration investment, which can improve corporate planning. Exploration expenditure is held to be a main indicator of economic activities in the oil and gas industry because exploration is supposed to lead to booking more reserves and increased production. A model was developed for analyzing the correlation between exploration expenditure and producer's reserves and production for conventional and unconventional gas plays in the United States. The model was used to quantitatively assess the exploration expenditures production and reserves of different producers for various conventional and unconventional gas plays. Producer's booked reserves, production from public sources, and reserves and production forecasts were incorporated into the model, which was used to analyze different types of exploration expenditure (land, drilling, and seismic) incurred at various times prior to reserves and production being booked. There was an overall positive correlation between exploration expenditure and reserves and production, but there was significant variance in the correlation between various producers operating in different plays. Unproved land acquisition was strongly correlated to the booking of proved reserves, but there was no correlation between unproved land acquisition and exploration expenditure ratio, reserves, or production. A number of companies had a high exploration expenditure to overall expenditure ratio, but the resulting payoffs were inconsistent. 6 refs., 1 tab., 6 figs.