Applied Petroleum Technology (Norway)

The purpose of this chapter is to discuss the codes and standards employed in the oil and gas industry in order to maintain high levels of safety valve quality and reliability. In accordance with law, contract, or industry practice, industrial equipment, including valves, must comply with codes, standards, and specifications. In different countries – even within the same country – and within different industries, these codes, standards, and specifications may differ. American Petroleum Institute (API), American Society of Mechanical Engineers (ASME), and the International Organization for Standardization (ISO) are the most common codes and standards for safety valves. Various ASME Boiler and Pressure Vessel Codes (BPVCs) and piping codes are briefly discussed. Also included are five API standards that address safety relief valves and relieving devices. A brief discussion is provided on BS 6759, which is no longer valid and consists of three parts. Additionally, Australian pressure safety valve AS 1271 is briefly discussed in this chapter. A brief explanation of hydrogen sulfide corrosion protection is provided by the National Association of Corrosion Engineers (NACE). In compliance with Pressure Equipment Directive (PED) 2014/68/EU and Pressure Equipment (Safety) Regulation 2016 (PE(S)R), pressure equipment destined for Europe and the United Kingdom must be marked with CE and UKCA.

It is necessary to install safety valves correctly in plants in order for them to function properly. Installation of safety valves is extremely important, since the correct installation of safety valves is just as important as the correct selection and sizing of the safety valves. According to studies, 75% of safety valve problems can be attributed to incorrect installation, even if the valves were properly selected and sized. In this article, some points that need to be considered before installing safety valves are briefly discussed. The location and position of safety valves are also discussed in this chapter. Additionally, the design and routing of inlet and outlet piping connected to safety valves is explained in more detail. It is described in detail the characteristics and requirements of isolation valves located on both inlet and outlet pipes as well as their locking requirements. In addition, the calculation of pressure drops for both inlet and outlet pipes is described in great detail. Last but not least, different rules are explained regarding the design of the outlet piping, including the selection of the outlet piping size based on a number of parameters, such as the allowable pressure drop in the outlet piping, which is typically set at 10% of the set pressure.

A combination of back pressure and sudden impulses generate reaction forces when the safety valve is open and blowing. Although the reaction forces at the inlet are relatively small, the majority of the reaction forces are generated at the outlet. This is due to the fact that high velocity and an increase in outlet pressure are expected. Particularly in the case of gas (compressible) service, the main reaction force is generated at the outlet. Taking into account the impact of the pressure safety valve (PSV) load, ensure that the pipework is adequately supported. It is important to note that reaction forces in safety valves are determined by the pressure of the fluid or gas flowing inside the valve as well as the size of the valve. Two safety valve standards explain how reaction forces are calculated: ISO 4126-9 and API 520. In accordance with ISO 4126-9, PSV reaction forces should be calculated based on steady-state flow conditions. A steady state flow is characterized by constant fluid properties throughout the system. According to API 520, different equations are provided for the calculation of reaction forces for gas, vapor, and steam services open discharge into the environment. To calculate the safety valve loads for open discharge of liquids and two-phase fluids, two separate equations are provided based on API 520. A limit for the acceptance of safety valve reaction forces is provided at the end of the chapter in accordance with ASME B31.3.

ABSTRACTOrthorhombic models are often used in the seismic industry nowadays to describe azimuthal and polar anisotropy and reasonably realistic in capturing the features of the earth interior. It is challenging to handle so many model parameters in the seismic data processing. In order to reduce the number of the parameters for P wave, the acoustic orthorhombic medium is proposed by setting all on‐axis S wave velocities to zero. However, due to the coupled behaviour for P and S waves in the orthorhombic model, the ‘S wave artefacts’ are still remained in the acoustic orthorhombic model, which kinematics needs to be defined and analysed. In this paper, we analyse the behaviour of S wave in acoustic orthorhombic media. By analysis of the slowness surface in acoustic orthorhombic media, we define the S waves (or S wave artefacts) that are more complicated in shape comparing to the one propagating in an acoustic transversely isotropic medium with a vertical symmetry axis. The kinematic properties of these waves are defined and analysed in both phase and group domain. The caustics, amplitude and the multi‐layered case for S wave in acoustic orthorhombic model are also discussed. It is shown that there are two waves propagating in this acoustic orthorhombic medium. One of these waves is similar to the one propagating in acoustic vertical symmetry axis media, whereas another one has a very complicated shape consisting of two crossing surfaces.

The Wilhelmøya Subgroup (Norian–Bathonian) is considered as the prime storage unit for locally produced CO2 in Longyearbyen on the Arctic archipelago of Svalbard. We here present new drillcore and outcrop data and refined sedimentological and sequence-stratigraphic interpretations from western central Spitsbergen in and around the main potential CO2-storage area. The Wilhelmøya Subgroup encompasses a relatively thin (15–24 m) siliciclastic succession of mudstones, sandstones and conglomerates and represents an unconventional potential reservoir unit due to its relatively poor reservoir properties, i.e., low-moderate porosity and low permeability. Thirteen sedimentary facies were identified in the succession and subsequently grouped into five facies associations, reflecting deposition in various marginal marine to partly sediment-starved, shallow shelf environments. Palynological analysis was performed to determine the age and aid in the correlation between outcrop and subsurface sections. The palynological data allow identification of three unconformity-bounded sequences (sequence 1–3). These sequences record intermittent deposition in the Early Norian, Early–Middle Toarcian, and Late Toarcian–Aalenian, interrupted by extended periods of erosion, bypass and/or non-deposition. The stratigraphically condensed development of the Wilhelmøya Subgroup in western central Spitsbergen is interpreted to be the result of very low subsidence rates coupled with a physiographic setting characterised by a very gentle depositional gradient. This facilitated rapid shoreline shifts in response to even relatively modest variations in relative sea level with considerable influence on the resulting depositional patterns. We present a revised depositional model for the regionally distinct Brentskardhaugen Bed at the top of the Wilhelmøya Subgroup involving condensation and partial reworking of a series of Upper Toarcian–Aalenian, high-frequency sequences. Coarse-grained extraformational fractions observed within conglomerates of the Wilhelmøya Subgroup are suggested to have been supplied from uplifted and exposed margins to the west (northern Greenland) and north (northern Svalbard).