The Raman lidar for atmospheric moisture sensing (RAMSES) for unattended, continuous multiparameter atmospheric profiling is presented. A seeded frequency-tripled Nd:YAG laser serves as the light source. A nine-channel polychromator, nonfiber coupled to the main telescope (790 mm diameter), is used for far-range measurements. Near-range observations are performed with a three-channel polychromator, fiber coupled to a secondary telescope (200 mm diameter). Measurement parameters are water-vapor mixing ratio (MR), temperature, and the optical particle parameters, which are extinction coefficient, backscatter coefficient, lidar ratio, and depolarization ratio at 355 nm. Profiles of water-vapor MR are measured from close to the surface up to 14 km at night and 5 km during the day under favorable atmospheric conditions in 20 min. Temperature profiles of the troposphere and lower stratosphere are determined with the rotational-Raman technique. For the detection of the rotational Raman signals, a new beamsplitter/interference-filter experimental setup is implemented that is compact, robust, and easy to align. Furthermore, the polychromator design allows two independent methods for calibrating measurements of depolarization ratio. RAMSES optical design concept and experimental setup are detailed, and a description of the operational near-real-time data evaluation software is given. A multiday observation is discussed to illustrate the measurement capabilities of RAMSES.

Abstract. A large-scale comparison of water-vapour vertical-sounding instruments took place over central Europe on 17 October 2008, during a rather homogeneous deep stratospheric intrusion event (LUAMI, Lindenberg UpperAir Methods Intercomparison). The measurements were carried out at four observational sites: Payerne (Switzerland), Bilthoven (the Netherlands), Lindenberg (north-eastern Germany), and the Zugspitze mountain (Garmisch-Partenkichen, German Alps), and by an airborne water-vapour lidar system creating a transect of humidity profiles between all four stations. A high data quality was verified that strongly underlines the scientific findings. The intrusion layer was very dry with a minimum mixing ratios of 0 to 35 ppm on its lower west side, but did not drop below 120 ppm on the higher-lying east side (Lindenberg). The dryness hardens the findings of a preceding study ("Part 1", Trickl et al., 2014) that, e.g., 73 % of deep intrusions reaching the German Alps and travelling 6 days or less exhibit minimum mixing ratios of 50 ppm and less. These low values reflect values found in the lowermost stratosphere and indicate very slow mixing with tropospheric air during the downward transport to the lower troposphere. The peak ozone values were around 70 ppb, confirming the idea that intrusion layers depart from the lowermost edge of the stratosphere. The data suggest an increase of ozone from the lower to the higher edge of the intrusion layer. This behaviour is also confirmed by stratospheric aerosol caught in the layer. Both observations are in agreement with the idea that sections of the vertical distributions of these constituents in the source region were transferred to central Europe without major change. LAGRANTO trajectory calculations demonstrated a rather shallow outflow from the stratosphere just above the dynamical tropopause, for the first time confirming the conclusions in "Part 1" from the Zugspitze CO observations. The trajectories qualitatively explain the temporal evolution of the intrusion layers above the four stations participating in the campaign.

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Summary The successful implementation of Lateral Jet PDC hydraulics has emerged over the last few years with quantifiable results. Lateral Jets set into the blades of the bit improve the cutter cleaning efficiency thereby increasing ROP. In addition to cleaning the plenum in front of the jet, fluid entrainment creates a venturi effect drawing the fluid across the blades serviced by the downward jets. This flow is then ejected at high speed to the junk slots. The operators of the North Sea Scott Field took a major initiative in this development, and in conjunction with the Lateral Jet company, expanded the technology to initiate a new cutter design and the second general of Lateral Jet type bits, the Fully Lateral Jet. This paper will track the development of the technology from the initial trials of Lateral Jets in the Scott Field, the rationale and design criteria that initiated oval PDC cutters and most recently the Fully Lateral Jet PDC drill bit. Introduction to Scott Field The Scott Field straddles Blocks 15/21 and 15/22 and is one of the largest fields to come onstream in the UKCS in the past few years (Fig 1). The first well drilled on the crest of the Scott structure was 15/22-3, drilled in 1977 This well encountered no sands of reservoir quality and it was not until 1983 that well 15/22-4 encountered oil bearing sands in what are now known as the Scott (C) sands of Block 1a. A follow-up down-dip appraisal well, 15/22-5, was a dry hole and estimates of the size of the accumulation were downgraded. It was not until the drilling of well 15/21a-15 in 1987 that the potential size of the accumulation became apparent. Rapid appraisal of the Waverly prospect as it was know by the 15/21 group, and the Brunei prospect as it was known by the 15/22 group, continued through to 1989 leading to Annex B approval in 1990 for the newly named Scott Field. In order to achieve a rapid build up to plateau production, seven sub sea production wells and seven associated water injection wells were drilling and completed prior to first oil. Drilling has continued with a programm of production wells being drilled from the production platform. The sub sea wells have been drilled from four different locations which in conjunction with the platform gives five separate surface clusters of wells (Fig 2). Lithology and Typical Well Design The lithology is similar to many neighbouring fields with oil being produced from Jurassic Sands. All directional work is completed in the 16" hole section before setting 13 3/8" casing in Paleocene shales. A 12 1/4" tangent section is then drilled through the lower Paleocene and Cretaceous, with 9 5/8" casing being set before the top of the Kimmeridge clay formation. An 81/2" section is then drilled to TD. Less toxic oil based mud is used from below the 20" casing shoe until TD (Fig 3). Established Drilling Practice in 12 1/4" Hole Considerable drilling has taken place in the immediate vicinity of Scott. Block 15/21 contains the producing Ivanhoe, Rob Roy and Hamish fields and had seen some forty wells drilled before the commencement of development drilling on Scott. A large amount of offset information was therefore available and considerable work had already been done to optimise bit selection and establish the suitability of PDC bits for the various formations.

A conventional approach to performance optimization resulted in some PDC performance improvements on the early wells of the Scott Field in Central North Sea blocks 15/21 & 15/22. This approach focused on the development and testing of individual bit features. Highly averaged performance measures such as bit run length and average penetration rate were used to quantify the influence of bit feature changes on bit performance. This approach left some of the variations in PDC performance unexplained. A co-operative drilling optimization study was conducted on two recent platform wells. This paper summarizes the results of the optimization study. focusing on the process and the benefits of identifying root causes of key drillability issues. It is shown that detailed analysis of footbased drilling data could explain many of the observed rate of penetration variances leading to consistently good drilling performance. P. 935