First Oman Implementation of Pressurized Mud-Cap Drilling Improves Drilling Efficiency and Sustainability

Drilling with a gas cap over the Natih formation in Oman often results in excessive flat time. Using the current dynamic fill equipment to deal with kick and loss scenarios leads to extensive nonproductive time on the rig. Managed pressure drilling (MPD) is a well-established drilling technology, and diverse variants exist to suit different requirements. All those variants use the rotating control device (RCD) as a common piece of equipment, but their procedures are different. The pressurized mud-cap drilling (PMCD) technique in the Natih formation replaces the need for traditional dynamic filling technology. The PMCD application enhances the drilling and completion processes by reducing flat time when total downhole losses are experienced. This paper elaborates on PMCD as a proven drilling technique in total loss scenarios when drilling with it for the first time in the Natih formation in Oman. It describes the PMCD process, the associated equipment, and the results of the inaugural application in the Qalah field.

SUPPORT FOR OFFSHORE MONOPILE INSTALLATION THROUGH THE TRENCH CUTTER TECHNOLOGY

Europe is currently facing an energetic revolution. Several offshore wind farm projects are currently under construction or under planning in North and Baltic Sea. Typical foundation structures for offshore wind farms are steel open-ended monopiles with large diameters up to 6 m. Currently, the monopiles are installed by driving with large impact hammers. However, there are many situations where pile refusal is reached, due to hard soil layers or erratic blocks. Driving and drilling technique is therefore applied. This manuscript briefly describes the trench cutter technology normally used for foundation works on land. Three case histories onshore and one offshore project are discussed and the evolution of the trench cutter technology for supporting the installation of offshore monopile is described.

Otoplastic Surgery for Calcified Auricular Deformity

Auricular hematoma is one of the most common problems among people who have got repetitive blunt trauma to the external ear. Prompt managements are drainage of hematoma and following prevention of re-accumulation (e.g. compression dressing). If the treatment is not successful, many complications can occur, including perichondritis, infection and necrosis. Especially long-lasting loss of blood supply to the ear cartilage and formation of neocartilage from disrupted perichondrium can result in cauliflower ear deformity. There were some studies trying to classify and to treat the cauliflower ear by the degree of deformities. And excision of deformed cartilage with reshaping of the auricle has been reported several times. In this article, we would like to introduce a successful drilling technique of otoplasty as a useful treatment option.

Comparison Between Surface and Near-Surface Residual Stress Measurement Techniques Using a Standard Four-Point-Bend Specimen

Background Determination of near-surface residual stresses is challenging for the available measurement techniques due to their limitations. These are often either beyond reach or associated with significant uncertainties. Objective This study describes a critical comparison between three methods of surface and near-surface residual stress measurements, including x-ray diffraction (XRD) and two incremental central hole-drilling techniques one based on strain-gauge rosette and the other based on electronic speckle pattern interferometry (ESPI). Methods These measurements were performed on standard four-point-bend beams of steel loaded to known nominal stresses, according to the ASTM standard. These were to evaluate the sensitivity of different techniques to the variation in the nominal stress, and their associated uncertainties. Results The XRD data showed very good correlations with the surface nominal stress, and with superb repeatability and small uncertainties. The results of the ESPI based hole-drilling technique were also in a good agreement with the XRD data and the expected nominal stress. However, those obtained by the strain gauge rosette based hole-drilling technique were not matching well with the data obtained by the other techniques nor with the nominal stress. This was found to be due to the generation of extensive compressive residual stress during surface preparation for strain gauge installation. Conclusion The ESPI method is proven to be the most suitable hole-drilling technique for measuring near-surface residual stresses within distances close to the surface that are beyond the penetration depth of x-ray and below the resolution of the strain gauge rosette based hole-drilling method.

Analytical Study of Early Kick Detection and Well Control Considerations for Casing while Drilling Technology

Recently, casing while drilling (CwD) technology has been employed to reduce drilling time and expenses. These intelligent drilling technique improved wellbore stability, fracture gradient, and formation damage while reducing exposure time but when a well control issue arises, the differences in wellbore geometries and related volumes compared to regular conventional drilling procedures necessitate a distinct strategy. In this paper, the essential well control parameters were provided for casing while drilling operations, presents simplified method that has been developed to evaluate the maximum kick tolerance (KT) for both conventional and casing while drilling techniques using a mathematical derivation, the narrow annular clearance, in contrast to drilling with a conventional drill string would impair kick detection and handling operations. Furthermore, the large disparity in kick tolerances should be carefully evaluated in order to avoid lost circulation/kick cycles as well as examine and evaluate technical approaches to early kick detection (EKD) studying how they relate to safety, efficiency, and reliability in a variety of common casing while drilling operations. According to preliminary findings, by utilizing casing while drilling technology and compared to identical well was drilled conventionally using drill pipe, the annulus pressure loss (APL) is average 3 times of the conventional drilling technique. Furthermore, kick tolerance is reduced by 50% and maximum allowable well shut-in time reduced by 65% necessitating early kick detection.

Determining Residual Stresses in Weld Joints of DN 850 Pipes by Spot Drilling Combined with Electronic Speckle Pattern Interferometry

Residual welding stresses affect significantly the strength, durability, and performance of structures. Therefore, there is an urgent need for developing and implementing techniques and equipment that allow reliably estimating stresses in experiments. This paper considers some aspects of the joint implementation of electronic speckle pattern interferometry and the spot drilling technique to determine these characteristics under the field conditions. The results of determining the distribution of residual stresses in the weld joint areas of DN 850 pipes are given for various welding modes. The study results are of independent significance and herewith, demonstrate the efficiency of the equipment developed to solve similar problems.

Deposition of dust with active substances in pesticides from treated seeds in adjacent fields during drilling: disentangling the effects of various factors using an 8-year field experiment

The side effects from the use of plant protection products and their potential effects on non-target arthropods (NTAs) such as honey bees, other insects within the vegetation layer and epigeic arthropods nowadays receive more attention. However, uncertainties about the factors driving the deposition of active substances (a.s.) into off-crop areas persist, in particular during sowing of treated seeds. Analysing a highly standardised 8-year field experiment, we assessed the importance of various factors potentially affecting dust drift and deposition of a.s., emitted during the sowing process of treated seeds and deposited on fields adjacent to the drilling field, i.e. on the ground, on flowers, and on nonflowering plant parts. Regarding a.s. deposition, the Heubach a.s. value has a predictive capability, which is independent from all other factors taken into account in this study, and can thus be considered as a scenario-independent measure of potential dust deposition. Petri dish samplers, an established standard method for measuring a.s. deposition, were representative of the results from the plant samplers for a given combination of drilling technique and adjacent crop type. Adjacent crop type is likely to impact on a.s. deposition. The present work will enable a more field-realistic exposure assessment for bees and other NTAs.