Use of Obturating Pills Combined with Low Concentration Acid Pills to Overcome Differential Stuck Challenges in Highly Deviated Wells

In 2020, A Major Offshore Operating Company in UAE faced a high differential pressure stuck event. This took place, during the execution of formation evaluation with a conveyed pipe sampling BHA. It is well known that after a differentially stuck pipe event happens, the success ratio will be time dependent (i.e. the less time a pipe remains stuck, the more chances there will be for it to become released) and the chances of releasing the BHA are always limited to the logging tools tensile limitations. One of the most common and successful methods to release differentially stuck BHA's specifically in limestone formations is by pumping and soaking acid pills. However, under such a high differential pressure environment, the use of acid may induce losses in the so called "thief zones", causing worse problems. The standard release procedure started by working the string within the tensile limits, followed by pumping acid pills (using the available volume mobilized before spudding each drilling section). During the first acid pills pumped to attempt to release the stuck pipe, loss volume pump rates, acid pill position(s) and coverage in the annulus was assessed and evaluated. Based on the results it was observed that the thief zone was in direct contact with the Pipe Conveyed circulation port, at the latching assembly. This then created a situation whereby, the acid pills were lost immediately after the acid came into contact with the formation. Utilizing low acid concentration pills also had the same effect. The solution was to pump an Obturating pill made-up of a weighting agent as a spacer behind the high volume, low concentration acid pill with crosslinking divergent chemicals, pumped at a high flow rate. This solution reduced the acid losses across the thief zone and once the Obturating pill came into contact with the loss zone, it facilitated the seal and cured the losses, by allowing the acid to move up the annulus until it reached the differentially stuck point and soaked across the problematic area. Once the acid pill was successfully placed at the required location using this method, the string was worked and successfully released. This combination of low concentration acid along with crosslinking divergent chemicals coupled with the Obturating pill behind the acid helped a major offshore operating company to pump the acid pill under partial losses only, to regain full circulation after only 10 bbl. of Obturating pill had entered inside the annulus. It allowed the acid pill to react across the stuck point, while keeping the string under low torque and compression. The operator was able to release the sampling BHA and bring it back to surface avoiding a lost in hole cost of around 4 MM$. The Obturating pill combined with low concentration CDC acid pill is proven to be a successful method in drilling operations when trying to release differentially stuck BHA's within a wellbore.

How Many Molecules Can Fit in a Zeolite Pore? Implications for the Hydrocarbon Pool Mechanism of the Methanol-to-Hydrocarbons Process

The methanol-to-hydrocarbons (MTH) process is a very advantageous way to upgrade methanol to more valuable commodity chemicals such as light alkenes and gasoline. There is general agreement that, at steady state, the process operates via a dual cycle “hydrocarbon pool” mechanism. This mechanism defines a minimum number of reactants, intermediates, and products that must be present for the reaction to occur. In this paper, we calculate (by three independent methods) the volume required for a range of compounds that must be present in a working catalyst. These are compared to the available volume in a range of zeolites that have been used, or tested, for MTH. We show that this straightforward comparison provides a means to rationalize the product slate and the deactivation pathways in zeotype materials used for the MTH reaction.

Thermo Acoustic Study of Salicylaldehyde in Carbon Tetra Chloride at 303.15K, 308.15K, 313.15K

Thermo-acoustic study in binary mixture of salicylaldehyde and carbon tetra chloride were reported at 303.15K, 308.15K, 313.15K. The molecular interaction have been carried out by computing various thermo acoustical parameters i.e. Intermolecular free length (Lf), Specific acoustic Impedance (Z), Molar Volume (Vm), Available Volume (Va), Isentropic compressibility (S) and other constant and the excess value of foresaid parameters have been evaluated by using ultrasonic velocity, density, viscosity data, the results of these parameters conclude the strength of molecular interaction. Keywords: Excess values of Salicylaldehyde, Acoustic Parameters, Molecular Interaction.

Towards the Automated Coverlay Assembly in FPCB Manufacturing: Concept and Preliminary Tests

In modern electronics, flexible and rigid-flex PCBs are largely used due to their intrinsic versatility and performance, allowing to increase the available volume, or enabling connection between unconstrained components. Rigid-flex PCBs consists of rigid board portions with flexible interconnections and are commonly used in a wide variety of industrial applications. However, the assembly process of these devices still has some bottlenecks. Specifically, they require the application of cover layers (namely, coverlays), to provide insulation and protection of the flexible circuits. Due to the variability in planar shape and dimensions, the coverlay application is still performed manually, requiring troublesome manipulation steps and resulting in undetermined time-cycle and precision.This paper aims at the improvement of the industrial process currently performed, by proposing an approach for the automation of Kapton coverlay manipulation and application. Since these products are commercially provided as a film with a protective layer to be removed, the peeling issue is addressed, representing a challenging step of the automated process; the results of a systematic series of tests, performed in order to validate the peeling strategy, are reported in the paper. The overall assembly strategy relies on the development of a customized multi-hole vacuum gripper, whose concept is presented and contextualized in the proposed assembly process by outlining a suitable workcell architecture.

Sedation Characteristics of Intranasal Alfaxalone in Adult Yucatan Swine

Compared with intravenous and intramuscular methods, intranasal administration of sedatives is a less invasive and nonpainful technique. In this prospective, randomized, crossover study, we evaluated the sedative characteristics of 2 doses(1 and 2 mg/kg) of alfaxalone administered intranasally to 7 adult Yucatan swine. We compared sedation scores before andafter administration of alfaxalone and between groups by using a composite sedation scoring system (range, 0 to 12, with12 being the highest level of sedation)). Pigs were randomly assigned to receive 2 doses of intranasal alfaxalone (1 mg/kg[A1]); 2 mg/kg [A2]) as 2 separate events in a crossover design with a 60-d washout period. Categories scored were posture,palpebral droop, uninhibited behavior, drowsiness, and acceptance of anesthetic facemask. Sedation scores were collected before sedation was administered and then every 3 min for 30 min afterward. Instilled volumes (mean ± 1 SD) were 5.7 ± 0.5 and 11.3 ± 0.8 mL for A1 and A2, respectively. Both alfaxalone doses produced significant increases in sedation scores compared with baseline. Median sedation scores for A1 (6; range, 4–12) were not different from those for A2 (6; range, 6 to 12). Intranasal administration of alfaxalone as the sole sedative agent increased sedation scores from baseline, achieving peak sedation at 6 to 9 min after instillation of A2. However, sedation scores were similar between the 2 groups, and neither dose produced sufficient sedation to facilitate handling or the performance of any clinical procedures. Given the concentration of alfaxalone solution currently available, volume is the major limiting factor regarding testing higher doses of this drug for its use as a sole sedative agent in swine.

DEVELOPMENT OF SCIENTIFIC BASIS FOR WATER MANAGEMENT IN AGROLANDSCAPES

Quantitative and qualitative depletion of water resources in Ukraine because of the increase in climate aridity make the problem of integrated surface and ground water management more urgent. The integrated management is based on the water balance of the territories, which automatically takes into account natural and artificial features of water use. The paper presents the results of a long term research aimed at resolving the problems of scientific support of integrated water resources management in Ukraine in the context of climate change. The plans for integrated water management are developed according to the administrative principle allowing optimization of the structure of water consumption and the assessment of available water resources capacity to meet water demand of the required quality without environmental risk for aquatic ecosystems and population. The surface and ground water in Ukraine have spatially homogeneous hydrochemical spectrum, which characterizes the concentration anions and cations in water and the nature of their change at different water exchange rates. Studies of hydrochemical spectrum have shown that its basic parameters are much higher for groundwater than for surface water. The results of the study on the spatial changes in the chemical composition of surface waters in the Dnipro river basin testify to the distinct homogeneity of their hydrochemical spectrum, which gives the reason to limit in practice observations of changes in the chemical composition of water to local points. As the experimental data are accumulated and the geospatial analysis of hydrochemical spectrum is made, the number of such points can be reduced ten times without significant negative impact on the reliability of the final results. It is possible to draw up a water balance with the use of correlation functions, the observance of which will guarantee the rational water resources use, based on their actual available volume and restrictions on the total water inflow, filtration losses, surface runoff (discharges). The water balance in the graphical representation is described by a linear function, which cuts the average of the sum of expendable elements on the ordinate axis over the entire observation period. The tangent of the slope of the graph represents the coefficient of water supply. The scope of this methodological approach's application is limited only by the availability of raw data. There are sufficient data from precipitation observations, water abstraction from all sources in volumes comparable to precipitation and more. It is also desirable to have observations of groundwater level fluctuations and air moisture deficit. The experimental research confirmed a high positive impact on the water resources formation made by forests, shelterbelts and meadows. In the humid zone it is possible to separate natural landscapes of wetlands and floodplains (60% of the territory), in the southern part - transitional landscapes that replace artificial agrolandscapes (40% of the territory). In arid climate conditions, the types of landscapes differ in the area of irrigated lands and the density of shelterbelts. Agrolandscapes are complex natural-technical systems. In most cases, when investigating their impact on the processes of formation and use of water, it is possible to operate a finite number of interconnected parts (subsystems). The purpose of such separation on subsystems is to obtain typical areas for which spatial structure of agricultural landscapes can be experimentally evaluated and the nature of its relationship with the factors of surface water resources formation can be determined. According to the assessment of water balance of rural territories, their water resources potential is equal to the sum of atmospheric precipitation and the volumes of water entering the balance space due to its withdraw for economic needs from surface and ground water bodies. When drawing up water balance for a hydrological year, water resources do not include precipitation, which is almost completely converted to river flow. The available volume of water for use should include the volume of water, the removal of which from natural or artificial circulation will not lead to negative environmental impacts or increase the cost of economic activity and restoration of fresh water bodies. The volume of water available for use is also limited by its qualitative indicators, which in turn are determined by its chemical composition (spectrum).

Experimental validation of an isoflux Earth coverage with a bimode ARMA antenna on a nanosatellite

Spatial telemetry links on nanosatellites require more and more reconfigurable beam antennas to improve the Earth coverage. The bi-mode Agile Radiating Matrix Antenna (8.0–8.4 GHz) was successfully designed to solve such kind of problems by using an isoflux mode associated with a switchable directive one. However, such an antenna introduces some manufacturing problems for the isoflux mode, mainly due to the small available volume on the nanosatellite platform. This paper describes a solution to this problem thanks to the ARMA concept. A comparison between theoretical and experimental results for the isoflux mode in circular polarization is presented to validate the results.

From 3D tissue data to impedance using Simpleware ScanFE+IP and COMSOL Multiphysics – a tutorial

Tools such as Simpleware ScanIP+FE and COMSOL Multiphysics allow us to gain a better understanding of bioimpedance measurements without actually doing the measurements. This tutorial will cover the steps needed to go from a 3D voxel data set to a model that can be used to simulate a transfer impedance measurement. Geometrical input data used in this tutorial are from MRI scan of a human thigh, which are converted to a mesh using Simpleware ScanIP+FE. The mesh is merged with electrical properties for the relevant tissues, and a simulation is done in COMSOL Multiphysics. Available numerical output data are transfer impedance, contribution from different tissues to final transfer impedance, and voltages at electrodes. Available volume output data are normal and reciprocal current densities, potential, sensitivity, and volume impedance sensitivity. The output data are presented as both numbers and graphs. The tutorial will be useful even if data from other sources such as VOXEL-MAN or CT scans are used.