All of the Arctic Eurasian Basins -the Barents and Kara Seas and the adjacent parts of the Pechora and West Siberian basins -have intracratonic settings and were affected by phases of intracratonic rifting during Riphean, Early Palaeozoic, Devonian-Early Carboniferous, Early Triassic, Jurassic and Cenozoic times. Often these stages were simultaneous at remote areas. The rifting led to the development of extensional sag basins giving thick sedimentary complexes associated with linear rifts and creating trends favourable for hydrocarbon generation. These trends are defined by the major fault complexes bordering them and include linear positive inverted structures and thick sedimentary complexes. The tectonic processes within these trends influenced the later structuring of the whole basin and the distribution of hydrocarbons. Hydrocarbon generation started long before the present basins' structural configuration formed, and oil and gas kitchens were associated mainly with extensional parts of the basins. Later phases of rifting and extension affected both the ancient oil and gas kitchens and the younger ones. Inversion caused trapping and affected fluid migration, mixing the petroleum systems. Inverted structures in the old rifts have the highest potential for large hydrocarbons accumulations but, in highly uplifted areas affected by faulting and erosion, exploration risk is high.

3D oil migration modelling of the Statfjord area of the Northern North Sea has led to increased understanding of the migration routes and definition of oil migration fairways. The majority of discovered fields in the Statfjord area lie on fault block ridges. Migration modelling demonstrates that they were filled by oil generated from the Viking Graben, East Shetland and Marulk basins, migrating stratigraphically downwards from the Upper Jurassic Draupne Formation source rock into the Middle Jurassic Brent Group sandstones. Thereafter, lateral migration in a fill–spill manner occurred along the axes of the ridges. Locally, petroleum also migrated laterally through both Upper and Lower Jurassic sandstones. The migration modelling has been combined with geochemical source rock and oil correlation resulting in increased confidence. For the first time we have been able to quantitatively model and visualize the complex petroleum system of the area and gain an insight into its development through geological time.

The first hydraulically operated completion was installed in Australia in 2004 (Guatelli et al 2004). Since then, a number of intelligent completions have been installed in offshore Australia. The remoteness of offshore Australia, particularly in the Timor Sea area, means intervention vessels are not readily available and well interventions are costly operations. For this reason, intelligent completion is considered to be an attractive alternative, by providing a down-hole solution to actively manage the reservoir production life and delay potential water breakthrough. The Kitan oil field is remotely located in the Joint Petroleum Development Area (JPDA) between East Timor and Australia. The Kitan oil field production facilities consist of three vertical producing wells, subsea flowlines, risers, and one Floating Production Storage and Offloading (FPSO) facility. The wells were completed with an intelligent design and cleaned up using a rig before the FPSO arrived on location. The intelligent completion design consists of two multi-stage hydraulic down-hole Flow Control Valves (FCVs) and three Down-Hole Gauges (DHGs) to independently control and monitor two different production zones. The FCVs have a total of 8 positions (fully opened, fully closed and 6 intermediate choke positions). It is planned to close the lower FCV to shut off water production from the lower zone while the upper FCV remains fully opened over the field life. The different FCV choke positions were utilized during the field startup and during the early stages of production while the water cut was still low, to overcome unforeseen technical limitations in the production system, and to optimize hydrocarbon production. This paper describes various aspects of the Kitan oil field intelligent well completion from design through installation and field startup to early stage of production operations, and includes technical problems encountered during the field startup as well as lessons learnt.

Iron-boracite from the English Zechstein IRON-BORACITE, (Fe, Mg, Mn)aBTO13CI, has been found in nodules in an anhydritic shale that overlies the sylvinite (sylvine-halite rock) of the third Zechstein Evaporite Cycle at the Boulby Mine, Loftus, Saltburn, Cleveland. This is the first record of the mineral in this country. The succession in the type roadway is:Anhydritic shale with the iron-boracite nodule bed near its base; the Shale and NoduleBeds are cross-cut by red sylvine-halite veins from the sylvinite below: 2 m.Pink-grey sylvinite with red and pink sub-horizontal colour bands; 2 m.Coarse-grained red and white halite with streaked-out fragments of anhydrite at its top; 3 m.

most peculiar coincidences :-(1) Renewal of eruption of Mont Pelee on morning of May 28 ; peculiar atmospheric disturbance at the Cape, simultaneous with earthquake shock there. (2) Renewal of irregularities in pressure curve on May 29 and 3 I and early morning of June 1, there being renewed volcanic disturbances in West Indies on or about these same dates. The curve for these last two days is remarkable, resembling closely a series of ripples and suggesting "interference" effects. Which was cause and which effect, or is there any correlation whatever? CHARLES STEWART. Meteorological Commission, Cape Town, July 16. A Tripartite Stroke of Lightning. AT about 6.50 p.m. on August 7, after two or three preliminary low thunder rumblings, which by no means prepared us for what was to come, a most tremendous crash of combined thunder, lightning and electric discharge burst right over my residence here. My butler, who was looking in the direction of our front gate, 80 yards to the north of our front door, saw a burst of smoke, mingled with a shower of leaves, rise into the air out of the adjoining shrubbery. My coachman, who was sitting just within the open door of the lodge, close to the front gate, was dazed by a vivid burst of flame at his feet which seemed to leap into the doorway. My neighbour's gardener, looking out of the lodge opposite, saw a nearly horiwntal flash of fire enter the shrubbery close to my front gate. A subsequent examination of the surroundings of the front gate and my coachman's lodge has revealed :-{ 1) A tearing up of the ground close to the massive iron post of the front gate, the splitting of a large flint at its foot, and a litter of ivy leaves on the gravel. (2) The clean cutting in two of an oak post, 35 yards distant to the northeast , from which an iron hand-gate was hanging. (3) The scorching of the outside foliage of a horse-chestnut some I 5 yards still farther off, in a direct line with the other two objects struck. In thirty years' experience of thunderstorms, which are rather frequent here, I have never observed the simultaneous striking of three different points by the electric discharge. A death-like stillness succeeded the crash, the storm appearing to have exhausted itself in a single tremendous explosion. Heavy rain was falling when the crash occurred. I have measured an inch and a half of rainfall within the last three days. Six Mile Bottom, Cambs., August 8. W. H. HALL.