The aim of this study is to explore the usefulness of hidden Markov models for lithological classification of geophysical measurements in boreholes. Standard statistical methods like linear and quadratic discriminant or cluster analysis treat the individual measurement points of well logs as independent samples of the underlying distribution. With hidden Markov models (HMM) the knowledge of sta...

The main task in oil and gas exploration is to gain an understanding of the distribution and nature of rocks and fluids in the subsurface. Well logs are records of petro-physical data acquired along a borehole, providing direct information about what is in the subsurface. The data collected by logging wells can have significant economic consequences, due to the costs inherent to drilling wells,...

Information about reservoir properties usually comes from two sources: seismic data and well logs. The former provide an indirect, low resolution image of rock velocity and density. The latter provide direct, high resolution (but laterally sparse) sampling of these and other rock parameters. An important problem in reservoir characterization is how best to combine these data sets, allowing the ...

In this paper we compare three different soft computing methods used as the well log data analysis model in petroleum engineering. Due to the diversely behaving nature, namely, that each region has a unique geophysical characteristic it is difficult to build a universal model relating the mathematical behaviour of the measured variables. This is the reason why soft computing techniques may be f...

Abstract Drilling deviated wells has become customary in recent times. This work condenses various highly and horizontal well log interpretation techniques supported by field examples. Compared to that vertical wells, is complex because the readings are affected not only host bed but also adjacent beds additional wellbore-related issues. However, understanding potential pitfalls combining infor...

One issue commonly found when working with well log data is the irregular abundance/availability of different recorded parameters. This especially applicable datasets collected in campaigns that may span through years, even decades, or companies. Artificial Intelligence be useful to fill gaps original database, resulting a more complete, standardised one. In this work we present workflow can fo...