In thin-layered reservoirs, drilling engineers face tough challenges—planning their drilling programs to follow the most productive reservoir layers while avoiding nearby water, gas or high-pressure zones. The rewards for a successful drilling strategy are clear—increased oil production and reduced water cut. In an oil field in the Persian Gulf, for example, oil production was increased four- t...

The drilling time data of gas logging are used to calculate drilling time ratio of the reservoir, and the total hydrocarbon data are used to calculate hydrocarbon contrast coefficient and to establish the drilling time ratio--hydrocarbon contrast coefficient crossplot. The standards of distinguishing the boundaries of hydrocarbon zones, hydrocarbonaceous water layers and dry layers are determin...

the narrow operating window between pore pressure and fracture pressure makes drilling difficult in some operations. a feasibility study of managed pressure drilling (mpd) is carried out on iran darquain oil field. the previous wells drilled in this field showed that mud returns were lost during drilling gadvan formation. the present work addresses this problem by means of surface back pressure...

OBJECTIVES There are no recognized analytical methods for measuring oil mist and vapours arising from drilling fluids used in offshore petroleum drilling industry. To inform the future development of improved methods of analysis for oil mist and vapours this study assessed the inter- and intra-laboratory variability in oil mist and vapour analysis. In addition, sample losses during transportati...

a r t i c l e i n f o The use of high-volume horizontal hydraulic fracturing (fracking) has increased substantially over the past five years in the United States. Use of this drilling technology to extract natural gas from hitherto impermeable shale is expected to increase even more in coming decades. Two institutions, integration contracts and well spacing requirements, evolved to mitigate the...

Recently, we have seen falling oil prices combined with sticky costs at a high level in the petroleum industry. This cause cost cuts and project postponements, thus challenging reserve replacement of oil companies and security of supply for consumers. Costs are particularly high for drilling. High rig rates are obviously important. In new contracts for high-spec semi rigs on the Norwegian Conti...

This paper explores the possibility of developing early warning indicators based on incident investigation. The use of early warning indicators may contribute to ensure that oil companies produce oil and gas without harmful spills. The incident investigated was a hydraulic oil leak from the Eirik Raude drilling rig during exploration drilling in the Barents Sea in April 2005. The incident is an...

Dermal exposure to drilling fluids and crude oil is an exposure route of concern. However, there have been no published studies describing sampling methods or reporting dermal exposure measurements. We describe a study that aimed to evaluate a wipe sampling method to assess dermal exposure to an oil-based drilling fluid and crude oil, as well as to investigate the feasibility of using an interc...

Given n potential oil locations, where each has oil at a certain depth, we seek good trade-offs between the number of oil sources found and the total amount of drilling performed. The cost of exploring a location is proportional to the depth to which it is drilled. The algorithm has no clue about the depths of the oil sources at the different locations or even if there are any. Abstraction of t...

Operational discharges of hydrocarbons from maritime activities can have major cumulative impacts on marine ecosystems. Small quantities of oil (i.e., 10 ml) results in often lethally reduced thermoregulation in seabirds. Thin sheens of oil and drilling fluids form around offshore petroleum production structures from currently permissible operational discharges of hydrocarbons. Methodology was ...