Hawaz Formation Research Articles

Permeability Prediction from Well Log Data Using Artificial Neural Networks: A Case Study of the Hawaz Formation in D-Field, Libya

Permeability is an important parameter in the characterization of any hydrocarbon reservoir. Yet, despite its vital importance, it is one of the most difficult and controversial petrophysical properties to calculate accurately due to nonlinearity and uncertainty in the dataset. Formation permeability is often measured in the laboratory from cores or evaluated from well test data. Core analysis and well test data, however, are only available from a few wells in a field, while the majority of wells are logged. The aim of this paper is to design an artificial neural network (ANN) model to predict formation permeability using a dataset from the Hawaz Formation in the D-field NC-186 concession, East Murzuq Basin, Libya. In this study, a back-propagation neural network (BP-ANN) model was built using the Python programming language. A total of 950 core horizontal permeability measurements and their corresponding well log data were collected from four wells to build the model. Traditional statistical analysis of the porosity/permeability relationship in cored well data yielded no reliable correlations for predicting permeability in uncored wells with R2 less than 15%. A supervised BP-ANN model was trained successfully and was successfully able to predict the permeability of the formations. Despite the presence of high reservoir heterogeneity, the permeability profile predicted by the ANN model using well log data agrees well with core permeability, which clarifies the applicability of this method.

تقييم الأداء الديناميكي لتكوين الحواز في حوض مرزق بليبيا كما يستدل عليه بتقنية التفسير السريع.

The evaluating of the Hawaz reservoir in the Murzuq basin based on the well recording data available for twelve exploratory were provided for this study. These records data have been examined through employing some cross-plots and use their outputs for controlling the interactive petrophysics software in order to identify the lithological constituents and fluid saturation parameters.The litho-saturation cross-plot indicated that the Hawaz Formation consists of sandstones with few shale.The Hawaz formation officially subdivided intoeight horizons, namely H1–H8. Horizons (H4 and H5) are the main reservoirs in Hawaz formation as all readings indicate its high resistivity, with positive differentiation between its different curves, high porosity, and low gamma ray. BVW min technology is introduced the fast method depends on calculating the minimum total water volume so that the reservoir is considered to contain irreducible water, meaning that water will not be produced with the oil. The value of BVW min was 0.05, meaning that any range for which the product of porosity multiplied by water saturation (Φ.SW) is greater than that value is excluded from any detailed calculations.Also, calculate the minimum value of electrical resistance (Rtmin=140ῼm) for oil production zones, where zones with electrical resistivity less than that value are excluded. Keywords: Hawaz Formation, H field of NC186, petrophysical parameters, well logging.

Facies Analysis of Middle Ordovician Hawaz Formation and the Major effect of the Ichnofacies on the Reservoir Quality, an Example from the NC115 Block in Murzuq Basin, Southwestern Libya

Facies Analysis of Middle Ordovician Hawaz Formation and the Major effect of the Ichnofacies on the Reservoir Quality, an Example from the NC115 Block in Murzuq Basin, Southwestern Libya

Sedimentary architecture of a Middle Ordovician embayment in the Murzuq Basin (Libya)

The Hawaz Formation comprises a siliciclastic, shallow to transitional marginal marine succession, deposited on the north-western cratonic margin of Gondwana during the Middle Ordovician. This unit is well documented in the north central part of the Murzuq Basin, where it is often dramatically truncated by Late Ordovician glaciation unconformities, generating a major discontinuity, not only in the studied area but also across the whole Saharan Platform of North Africa. The Hawaz Formation is particularly relevant as one of the two major oil-bearing reservoirs in the Murzuq Basin. However, Late Ordovician erosion ensures that its present configuration bears very little relation to the original sedimentary architecture and, consequently, there is a need for a detailed large-scale correlation and sedimentary reconstruction of the Hawaz in order to improve subsurface management of this reservoir unit. The present study was developed from a previous sedimentological characterization of the Hawaz Formation, based on subsurface data provided by 35 wells. This sedimentological background provided the basis for the reconstruction of the sedimentary architecture of this unit by means of eight correlation panels oriented along both sedimentological dip (NNW-SSE) and strike (WSW to ENE). In addition, a series of Gross Depositional Environment (GDE) maps were also generated with the aim of providing insight into the lateral distribution of facies belts within the framework of a sequence stratigraphic-based reservoir zonation. The results of this study suggest that the Hawaz Formation was deposited in a relatively protected or embayed shoreline with multiple bays/estuaries as the main entry points for sediment into the basin, most likely influenced by the effects of pre-existing north-northwest to south-southeast Pan-African structures controlling local accommodation space and reactivated during Ordovician times. Correlation panels and GDE maps also show the Hawaz Formation to be an extensive and continuous reservoir across the studied area, deposited in a broadly extensive subtidal to intertidal paralic environment, with very few or possibly no modern sedimentary analogues.

Sedimentology of a “nonactualistic” Middle Ordovician tidal-influenced reservoir in the Murzuq Basin (Libya)

The subsurface of the highly productive Murzuq Basin in southwest Libya remains poorly understood. As a consequence, a need exists for detailed sedimentological studies of both the oil-prone Mamuniyat Formation and Hawaz Formation reservoirs in this area. Of particular interest in this case is the Middle Ordovician Hawaz Formation, interpreted as an excellent example of a “nonactualistic,” tidally influenced clastic reservoir that appears to extend hundreds of kilometers across much of the North African or Saharan craton. The Hawaz Formation comprises 15 characteristic lithofacies grouped into 7 correlatable facies associations distributed in broad and laterally extensive facies belts deposited in a shallow marine, intertidal to subtidal environment. Three main depositional sequences and their respective systems tracts have also been identified. On this basis, a genetic-based stratigraphic zonation scheme has been proposed as a tool to improve subsurface management of this reservoir unit. A nonactualistic sedimentary model is proposed in this work with new ideas presented for marginal to shallow marine depositional environments during the Middle Ordovician in the northern margin of Gondwana.

Palynology of the Middle Ordovician Hawaz Formation in the Murzuq Basin, south-west Libya

ABSTRACTTwenty-nine core and seven cuttings samples were collected from two boreholes penetrating the Middle Ordovician Hawaz Formation in the Murzuq Basin, south-west Libya. The samples were palynologically analysed in order to determine age and depositional environment. The palynological assemblages contain abundant sphaeromorphs, rare but diverse acritarchs, rare chitinozoans, and relatively abundant cryptospores. A total of 26 acritarch species, five chitinozoan species and 17 cryptospore species have been identified. The acritarch and chitinozoan assemblages provide biostratigraphical age dating and indicate that the Hawaz Formation is Mid Ordovician and most likely mid Darriwilian (Llanvirn) in age. The cryptospore assemblage is typical of those from the Mid Ordovician–earliest Silurian and does not permit further age refinement. Based on palynofacies analysis, the depositional environment of the Hawaz Formation is interpreted as shallowing upward from nearshore marine inner shelf to marginal marine. The cryptospores provide rare evidence for Middle Ordovician terrestrial vegetation at this very early stage in its development.

Integration of seismic interpretation and petrophysical studies on Hawaz Formation in J-field NC-186 concession, Northwest Murzuq basin, Libya

This study has been carried out by the integration of seismic interpretations and the well-logging analysis of ten wells distributed in J-field of concession NC-186, Murzuq basin, Libya. Twenty (3D) seismic lines and ten wells have been analyzed. The results of this study indicated that, the main reservoir in this concession is Hawaz Formation. Hawaz has been split into 8 units with a subdivision of Hawaz H4 into three subunits with the objective of better characterization of the three general fine upward intervals. The lower interval of H4 zone presents the better reservoir properties. The depth of reflector H4 ranges from 4100ft in the northwestern part of the study area and increases to 4600ft in the southeastern part of the study area. In this study, the outline of the Hawaz paleohighs which is NC-186 Field “J” is generally trending in the NW-SE direction. The well logging analysis particularly quick look interpretation indicates that Hawaz Formation in the studied wells is mainly oil-bearing with some water-bearing sand levels at the horizons from H4 to and H6 which are potentially the main reservoirs. The water bearing zones are beyond these horizons starting from the sub-horizon H6c and the oil water contact is probably at depth 4495ft. The crossplot of porosity-saturation for H5 and H6b indicates firmly that these horizons are indeed at irreducible state and will produce mainly oil as indicated in J4-NC186 well, while the crossplot of H8 shows wide scattering of points which is the main characteristic for water producing horizon. The depth of Hawaz Formation H4 is more than 4160ft in J4, J12 and J16 wells in the northwestern parts of this field and increases to 4400 in the central part of the concession at well J1.

Reservoir quality of Hawaz Formation, J oil field, Concession NC186, NW Murzuq basin, SW Libya

The present paper deals with evaluation of petrophysical parameters of Hawaz Formation at J oil field, Concession NC186 in Murzuq basin through the analysis of well-logging data available for ten exploratory wells. A comprehensive formation evaluation has been applied through numbers of crossplots and use their output parameters as input data for interactive petrophysics software (IP) in order to evaluate the lithological constituents and fluid saturations. The lithosaturation crossplots indicated that the Hawaz Formation consists of sandstones with few shale. These sandstones are generally fine to very fine grains but occasionally coarse to very coarse grained, and coursing upward sequence is indicated. The lithosaturation crossplots also illustrated that horizons H4 and H5 are the main reservoirs in Hawaz formation.

Reservoir quality of Hawaz formation, J oil field, concession NC186, NW Murzuq basin, SW Libya

The present paper deals with evaluation of petro-physical parameters of Hawaz Formation at J oil field, Concession NC186 in Murzuq basin through the analysis of well-log data available for ten exploratory wells, distributed in J oil field. A comprehensive formation evaluation has been applied through numbers of cross-plots and using their output parameters as input data for interactive petro-physics software (IP) in order to evaluate the lithological constituents and fluid saturations. The litho-saturation cross-plot indicated that the Hawaz Formation consists of sandstones with few shale. These sandstones are generally fine to very fine grains but occasionally coarse to very coarse grained. Generally coursing upward sequence is indicated. The litho-saturation cross-plots also illustrated that horizon H4 and H5 are the main reservoirs in Hawaz formation

Petrophysical characteristics of Hawaz formation, H oil field, concession NC186, NW Murzuq basin, SW Libya

Petrophysical characteristics of the Hawaz Formation in H oil field, Concession NC186 of Murzuq basin have been evaluated through the analysis of well-logging data recorded for ten exploratory and development wells. These records have been analyzed through utilizing some cross-plots and use their outputs for controlling the interactive petrophysics software in order to identify the lithological constituents and fluid saturation parameters. The litho-saturation results indicated that Hawaz Formation is mainly oil-bearing Horizons H4 and H5 are the main productive zones. The evaluation reveals also that the lithological facies consists mainly of sandstone. This facies is characterized by coarsing upward.

Hydrocarbon probability of Middle Ordovician Hawaz Formation, Murzuq Basin, Southwestern Libya

The Middle Ordovician Hawaz clastic reservoir on the Murzuq Basin is a new exploration play of great importance in the NC186 concession. H-field is one of the new discoveries in this concession. The main target of this investigation is to detect and evaluate the hydrocarbon play of Hawaz Formation in H-field. Petrophysical characteristics and seismic interpretations of the Hawaz Formation in H oil field, Concession NC186 of Murzuq basin have been evaluated through the analysis of well-logging records of ten exploratory wells and 3D seismic sections distributed in H oil field. These data have been analyzed and interpreted through utilizing some analytical cross-plots. The lithosaturation analysis indicates that the Hawaz Formation is mainly oil-bearing with some water-bearing sand levels with thickness ranging from 550 ft in the northwestern part of this field and increasing to more than 640 ft. The average cutoff of H-field illustrated that the water saturation is 45 %, the porosity is 12 %, and the reservoir thickness is 190 m. This surface was picked at 840 ms (TWT) in the northwestern part of the study area and increased to 1060 ms (TWT) in the southeastern part of the study area. The Hawaz surface was located at depths ranges from 4360 ft in the H1-NC186 well in the northwestern part and increased to 4611 ft in the H3-NC186 well in the southeastern part of the H-field. The analytical formation evaluation reveals that the lithological facies consists mainly of sandstone and little shale. This sandstone is coarsening upward. The lateral distribution of the petrophysical parameters portrays that the Hawaz Formation is a good reservoir rock where H4 and H5 horizons are the main productive zones.

Early Palaeozoic evolution of Libya: perspectives from Jabal Eghei with implications for hydrocarbon exploration in Al Kufrah Basin

AbstractThis paper presents new stratigraphic and sedimentological data of the Ordovician, Silurian, and Mesozoic succession exposed on the western flank of Al Kufrah Basin. Field data (logged sections, photographs, palaeocurrent analyses) are presented from the Jabal Eghei region. This region lies ca. 200 km E of the closest stratigraphic tie point at Mourizidie on the eastern flank of the Murzuq Basin. The succession starts with the Hawaz Formation (Middle Ordovician) comprising >100 m of cross‐bedded and bioturbated sandstones that are interpreted as deposits of tidal currents in an open shelf setting. The contact between the Hawaz and Mamuniyat formations is an erosional unconformity, incised during advance of Late Ordovician ice sheets towards the NE. The Mamuniyat Formation comprises >150 m of massive and graded sandstones tentatively assigned to the Hirnantian, and contains an intraformational, soft‐sediment striated surface that is interpreted to record re‐advance of ice sheets over Jabal Eghei. The outcrop section suggests the sandstone would form an excellent reservoir in the subsurface. The Mamuniyat Formation is overlain by the Tanezzuft Formation (uppermost Ordovician–lowermost Silurian). This includes sandy limestone/calcareous sandstone, a Planolites horizon, and then 50 m of interbedded shale, silt and fine‐grained, graded and hummocky cross‐stratified sandstone recording deposition from both shallow marine turbidity currents and storm flows. A striated pavement in the lower part of this sequence is overlain by calcareous lonestone‐bearing intervals (interpreted as ice‐rafted debris). These features testify to late phases of glacial advance probably post‐dating the regional Hirnantian glacial maximum. The basal Silurian ‘hot shale’ facies is not developed in this area, probably because late glacial advance suppressed the preservation of organic matter. The upper part of the Tanezzuft Formation is truncated by an unconformity above which palaeosol‐bearing fluvial deposits (undifferentiated Mesozoic) occur.

Sandstones, glaciers, burrows and transgressions: The Lower Palaeozoic of Jabel az-Zalmah, Al Kufrah Basin, Libya

Field studies in the Jabel az-Zalmah region, at the northern flank of Al Kufrah Basin provide new insights into the stratigraphy and evolving depositional environments of Cambro–Ordovician through Devonian sediments. At the base of the succession, the Hawaz Formation is about 300m thick and is characterised by frequently Skolithos-burrowed, fine to medium grained sandstones with occasional silty intervals and rare conglomerates deposited in a generally high-energy tidal shelf setting. Bioturbation is pervasive, and includes spectacular Cruziana traces produced by Early to Mid Ordovician trilobites at the bottom and the top of the Hawaz Formation respectively. These strata were incised during the late Ordovician (Hirnantian) glaciation. Ice sheets flowing over Jabel az-Zalmah cut a palaeo-topography of up to 100m relief. This relief is overlain by a coarsening upward succession of clastic sedimentary rocks, recording re-advance of an ice sheet, which overrode the uppermost sandstones. Ice sheet retreat was accompanied by marine transgression and erosion, which left a thin transgressive lag-conglomerate, capped sharply by siltstones of the Tannezuft Formation. Progradation resumed after post-glacial maximum flooding, depositing tide, storm, and river-influenced parasequences of a major delta complex (200m thick Acacus Formation). Fluvial incision, and the development of a disconformity, preceded the deposition of the Tadrart Formation (50m thick), a succession of trough-cross bedded braided river deposits. Transgression, and the re-establishment of shallow or marginal marine systems, is represented by the extensively bioturbated Binem Formation in which Zoophycos burrows offer a tentative Middle Devonian stratigraphic fix. An understanding of the lithological character of the Lower Palaeozoic strata in Jabel az-Zalmah, together with the character of unconformities that punctuate the succession, will be vital for successful hydrocarbon exploration in this frontier basin which has, until now, been unsuccessful.

Trace fossils and depositional environments in the Hawaz Formation, Middle Ordovician, western Libya

The ichnology of the Middle Ordovician Hawaz Formation in the Gargaf uplift (W Libya) is here reported. Eleven ichnogenera have been identified in this shallow marine formation: Arthrophycus, Bergaueria, Cruziana, Daedalus, Lockeia, cf. Psammichnites, Planolites, Rusophycus, Skolithos, Teichichnus and Thalassinoides. Their distribution is clearly linked with lithofacies and depositional paleoenvironments. Nearshore to shoreface sandstone facies are characterized by dense, piperock occurrences of Skolithos, which is a characteristic association in high-energy, sediment-shifting, shallow marine settings in the lower Paleozoic. This Skolithos ichnofacies is related to regressive sand belts prograding during high-stand sea level conditions. In contrast, heterolithic facies, most abundant in transgressive intervals, are dominated by horizontal burrows and trails, characteristic of the Cruziana ichnofacies. Higher diversity is achieved in those heterolithics found as forming part of the storm-dominated facies association, while similar facies associated to tidal deposits exhibit a less variety and abundance of traces indicating less favorable ecological conditions.

Glaciation and deglaciation of the Libyan Desert: The Late Ordovician record

Detailed outcrop studies at the flanks of Al Kufrah Basin, Libya, reveal the nature of glacially-related sedimentation and post-depositional deformation styles produced in association with the Late Ordovician glaciation, during which ice sheets expanded northward over North Africa to deposit the Mamuniyat Formation. At the SE basin flank (Jabal Azbah), the Mamuniyat Formation is sand-dominated, and incises interfingering braidplain and shallow marine deposits of the Hawaz Formation. The glacially-related sediments include intercalations of mud-chip bearing tabular sandstones and intraformational conglomerates, which are interpreted as turbidite and debrite facies respectively. These record aggradation of an extensive sediment wedge in front of a stable former ice margin. An increase in mudstone content northward is accompanied by the occurrence of more evolved turbidites. A widespread surface, bearing streamlined NW–SE striking ridges and grooves, punctuates this succession. The structures on the surface are interpreted to have formed during a regional north-westward ice advance. Above, siltstones bearing Arthrophycus burrows, and Orthocone-bearing sandstones beneath tidal bars testify to glaciomarine conditions for deposition of the underflow deposits beneath. By contrast, the northern basin margin (Jabal az-Zalmah) is appreciably different in recording shallower water/paralic sedimentation styles and major glaciotectonic deformation features, although facies analysis also reveals northward deepening. Here, a siltstone wedging from 8 to 50 m toward the north was deposited (lower delta plain), succeeded by climbing ripple cross-laminated sandstones up to 60 m in thickness (distal through proximal delta mouth bar deposits) with occasional diamictite interbeds. These rocks are deformed by thrusts and > 50 m amplitude fault-propagation folds, the deformation locally sealed by a diamictite then overlain by conglomeratic lag during ultimate deglaciation. Integrating observations from both basin margins, a model of fluvial-dominated delta systems feeding a pulsed debrite and turbidite fan system in a shallow proglacial shelf is proposed.

AN INTEGRATED STUDY OF DIAGENESIS AND DEPOSITIONAL FACIES IN TIDAL SANDSTONES: HAWAZ FORMATION (MIDDLE ORDOVICIAN), MURZUQ BASIN, LIBYA

Studies of the impact of diagenesis on reservoir quality in tidal sandstones can be of great importance in successful hydrocarbon exploration. The study reported here shows that diagenetic alterations and bioturbation have induced considerable deterioration and heterogeneity in the reservoir quality of the sand‐dominated tidal deposits of the Middle Ordovician Hawaz Formation in the Muruq Basin, Libya. Comparison is made between the diagenetic evolution of samples from the subsurface (present‐day depth 1500 m) and from surface outcrops in order to study the impact of burial and uplift on the spatial and temporal distribution of reservoir quality in the Hawaz Formation sandstones.Eogenetic alterations, which were mediated by meteoric water circulation, included kaolinitization and dissolution of framework silicates and mechanical compaction. Mesogenetic alterations (T > 70°C; depth > 2 km) included pressure dissolution of quartz grains and concomitant quartz cementation, conversion of kaolinite into dickite, illitization of kaolinite and of grain‐coating clays, and the precipitation of Mg‐rich siderite cement. Reduction of intergranular porosity was due more to compaction than to cementation, yet quartz overgrowths are up to 16% in some of the sandstones. Bioturbation has resulted in a greater reduction in sandstone permeability in the lower part of the formation than the upper part. A higher ratio of dickite to kaolinite in subsurface samples than in outcrop samples is attributed to the longer residence time of the former sandstones under mesogenetic conditions. Telodiagenesis has not resulted in enhancement of reservoir quality of the Hawaz Formation Sandstones but in pseudomorphic calcitization of siderite and oxidation of pyrite to goethite.This study shows that the reservoir‐quality evolution of tidal sandstones can best be elucidated when linked to depositional facies and distribution of diagenetic alterations.

Stratigraphy and sedimentology of the Middle Ordovician Hawaz Formation (Murzuq Basin, Libya)

The Middle Ordovician Hawaz Formation is a 200-m (660-ft)-thick succession made up of fine-grained quartzarenites displaying a variable degree of bioturbation. It records the deposition in a large-scale, low-gradient estuary, which was partially controlled by tectonic extension. The upper boundary of the formation is marked by two erosion surfaces (unconformities U1 and U2), related to the Late Ordovician glaciation. The U1 and U2 erosion surfaces generated a pronounced paleotopography that controlled the deposition of the Upper Ordovician sequences. Tectonism influenced the paleogeography, although faults were unimportant from the point of view of sedimentary thickness. Tectonic subsidence was moderate, and accumulation rates were low. Physiography favored tidal power, especially during transgressive episodes, when the coastal embayment was flooded. We defined 11 lithofacies, forming 6 facies associations. These associations are subtidal sandstones; storm-reworked, shoreface sandstones; shoreface-to-beach sandstones; channel-sandstone bodies; nearshore to inner-platform sandstones; and K-bentonites. Trace-fossil assemblages match Skolithos and Cruziana archetypal ichnofacies. On the basis of the dominant facies associations and ichnofacies, we divided the formation into three informal units, from base to top: HW.1, HW.2 and HW.3. Periodically, volcanic ash was supplied to the basin from distal eruptive centers and was preserved as thin beds of K-bentonite interstratified with the shoreface sandstones, but not with the tidal-dominated sandstones. We divided the Hawaz Formation into five third-order depositional sequences. Lowstand deposits were not identified. The lower boundaries of transgressive systems tracts are tidal ravinement surfaces or sequence boundaries, whereas the upper boundaries are flooding surfaces. The transgressive systems tracts are constituted by early transgressive tidal deposits separated by a wave ravinement surface from the late transgressive storm-dominated deposits. Highstand systems tracts consist of bioturbated shoreface-to-beach sandstones, which record seaward, shoreline progradation. Emilio obtained his Ph.D. in geology from the Universitat de Barcelona in 1988. Since then, he has been a lecturer in basin analysis and petroleum geology. He has been involved in several research projects on sedimentology and basin analysis in Spain, northern Africa, Antarctica and South America. His present-day research interests include three-dimensional modeling of sedimentary bodies and reservoirs. A professor of stratigraphy at the Universitat de Barcelona, M. Marzo's research interest focuses on the application of clastic sedimentology, sequence stratigraphy, reservoir modeling, and basin analysis to the exploration and production of hydrocarbons. He has been involved in several research projects funded by oil companies in southern Europe, the North Sea, South America, and northern Africa. Jordi M. de Gibert received his Ph.D. from the Universitat de Barcelona in 1996. After a period at the University of Utah, he returned to Barcelona in 1999, where he currently holds a position as a tenure-track lecturer. His interests and areas of expertise include trace fossils, their paleobiological significance, and their implications for understanding ancient depositional environments. K. Tawengi received a B.Sc. degree in geology from Alfateh University, Libya, in 1984, and an M.Sc. degree in sedimentology and stratigraphy from Durham University, England, in 1996. He worked as an explorationist with Agip Oil Company in Libya from 1985 to 2000 and since then has worked as a senior exploration member with REPSOL Exploration in Murzuq S.A. His main fields of interest are sedimentology, stratigraphy, and subsurface geology. A. Khoja graduated in 1972 from the University of Libya. He received a diploma in petroleum geosciences from Oxford Polytechnic (1991) and an M.Sc. degree from Oxford Brookes University (1993). He joined the National Oil Corporation of Libya in 1972 and is presently the regional studies superintendent in the National Oil Exploration Department. Nestor obtained his degree in geology from Cordoba University (Argentina) in 1982 and his postgraduate in petroleum geology in the University of Cuyo, Argentina. He joined YPF in 1984 and worked in their exploratory department in Mendoza, Plaza Huincul, and Neuquen until the year 2000. Subsequently, he became Libya team leader for REPSOL- YPF in Madrid. He is currently director of exploration and production in Brazil.