In this paper results are presented from experiments in which the pressure loss in single-phase pipe flow is studied when radial inflow occurs. Experiments have been carried out with pipes which have different perforation geometries so as to be able to investigate the effect of perforation geometry on the pressure loss. Data analysis of these experiments, as well as analysis of experiments carried out by other groups, yields a pressure loss model which accurately describes pressure losses in single-phase pipe flow with radial inflow through perforations in the pipe wall. The experimental data is subsequently used to establish a numerical value of a parameter which is used in a model description. This leads to the formulation of an effective friction factor for pipe flow with radial inflow.

In this paper, results are presented from an experimental comparison between a light hydrocarbon system from the North Sea and a model oil system in pipe flow. The experiments were carried out in order to compare similar fluid systems (density, viscosity, oil-water interfacial tension) with respect to pressure drop and flow pattern for horizontal flow. The results show significant deviations with respect to pressure drop and flow patterns for two and three-phase flow. This may contribute to the explanation of the discrepancies often revealed between multiphase models and measurements on multiphase flowlines in the oil and gas industry.

Whilst significant efforts have been made worldwide on developing solutions for capping offshore blowouts, less has been done to ensure safe and reliable kill operations through a relief well. This paper presents new solutions to challenging kill operations.Well-kill operations through a relief well are still considered the most reliable and ultimate method for killing a blowing well. Strict legislation has been enforced for such operations, which challenges technical operational limits and margins. The requirement to be able to dynamically kill a blowing well through one single relief may restrict well design and thereby reduce contingencies.By pumping of ultra-high density kill fluid (UHDKF) or by injecting a slug of UHDKF as part of a staged well-kill operation, more reliable operations can be planned for with reduced pumping pressures, reduced horsepower requirements, significant fluid volume reductions and cost reductions. Furthermore, these ultra-high density fluids can enable kill operations that would otherwise require changes to the original well design.Some ultra-high density kill fluids have been formulated based on high density cesium brines. A clear brine with a density of 3.20 g/cm 3 and very low viscosity has been formulated by blending cesium phosphate and cesium tungstate brines. Higher densities can be achieved by adding a small amount of solid weighting material to cesium brines.The new ultra-high density kill fluids represent a great technological step. It is recommended that the findings presented in this paper are implemented in future Blowout Contingency Plans in order to ensure sufficient operational margins in the relief well planning and the kill programs.

Breakthroughs of water and/or gas in production wells may have direct consequences for the production rates and overall field recovery factors. Multiple technologies have recently been developed to autonomously control inflow from the reservoir. Common to all these technologies is that new limitations are introduced which may have a negative impact on the well. This paper presents the design process for the next generation inflow control system and introduces new requirements for such completions. Traditional Passive Inflow Control Devices (ICD) are designed to act in a preventive manner by setting up a somewhat more even inflow profile along the reservoir section and thereby delay the breakthrough of gas or water. More recently, several new initiatives have been presented which will operate autonomously and try to choke back unwanted production. Common to all these technologies is that viscosity differences are used to identify the flowing fluid phases. Viscosity differences between the reservoir fluids are therefore mandatory for these to work. In this work the design process has been given an operational focus and the following requirements for the next generation autonomous inflow control devices have been defined: easy to install as an integrated part of the downhole completionrobust in design and functionalitysecures complete clean-up of mud and completion fluidsindependent of fluid viscositynegligible pressure drop during normal productionallows back-flow of fluids In this paper a new design is proposed for the next generation autonomous inflow control valve which is independent on differences in fluid viscosities. The proposed valve blocks, or restricts, production of unwanted water or gas, and re-opens for production if oil comes back. It can be designed to stop water/gas production at a predetermined WC/GOR. Furthermore, the valve ensures efficient clean-up along the full length of the reservoir section and is insensitive to exposure to mud, particles and filtercake. The valve will not restrict any future well operations and can be designed with a fail-safe option. The new design of autonomous inflow control systems represents a great technological improvement which will ensure robust, economical and fail safe design as well as removal of typical operational envelopes necessary for traditional technologies.

The Influx Management Envelope (IME) is a tool for operational decision making when managing influxes in Managed Pressure Drilling (MPD) operations. There have been numerous developments to the IME in recent years, and it is gaining traction over the MPD Operating Matrix (MOM). Calculation of the IME can be done in different ways. The original approach of calculating an IME described in (Culen et al. 2016), give less acceptable influx sizes than using multiphase simulations. Some of this can be attributed to the used Equation of State (EOS), and some to the distribution of gas in the wellbore. There is ongoing work for creating purpose-built tools for generating IME's that consider the gas as a single bubble, but with a real gas EOS, as well as considering gas distribution. In this work, the sensitivity to the model used when creating an IME is studied. This is done through comparing the single-bubble real-gas IME by (Berg et al. 2019) with IME's generated using Drillbench Dynamic Well Control as well as the commercial multiphase flow simulator Ledaflow for synthetic test wells. Discrepancies between the results are discussed and the differences in the underlying model and calculation procedure with respect to the end IME is elaborated.