Tieto (Czechia)

Abstract Objectives/Scope Recently Abu Dhabi National Oil Company has called Whitson (PERA), a world leading PVT modelling consultancy company, to develop a best practice methodology/tool to quantify the condensate liquid production originating from the gas cap that is produced through oil rim producers' wells. This practice is integrating simulation work with field measured data and provided for the first time a solution to an oil and gas industry challenge, which is causing a conflict of interest between shareholders especially when oil rim and the associated gas cap are belonging to different concessions. Methods, Procedures, Process The work has been done for a giant oil field with large gas cap (rich in condensate) where only the oil is being developed since the 1960s. Initially the production GOR was limited to RS, but in 2010 the development strategy changed, and the field was being produced at GOR higher than RS allowing free gas from Gas Cap (rich with condensate) to be produced with oil. The question then arised of how much condensate is being produced through the oil rim producers. The condensate allocation method makes use of all measured well test data (Qo, GOR and API) and compositional reservoir simulation results. The used EOS (equation of state) model has been tuned to all available laboratory PVT data. This method uses a history-matched, reservoir simulation model run with a "dual-EOS" that is constructed by duplicating the tuned EOS model into two identical EOS models - one for the initial gas cap, and the other one for the initial oil zone. The dual- EOS run gives identical performance to single EOS model run. The generated dual-EOS compositional wellstreams are adjusted (1) to honor exactly the historical well test GOR data for each well, and (2) to honor as best possible the historical well test APIs for each well. The resulting wellstream will honor exactly the simulation model oil rates of each well throughout history, exactly the measured well test GOR, and close-to-exact APIs for each well. The final altered well streams are processed through a 4-stage field separator, yielding the well total stock-tank oil and condensate volumes. Results, Observations, Conclusions Historical gas cap condensate volumes produced from wells completed in the oil rim has been achieved during the field history. This was made possible by using (1) well production test data (GORs and APIs), (2) results from a history-matched compositional model, (3) tracking of components originally found in gas cap and in oil rim, and (4) application of a tuned EOS model. The conclusion is that such an integrated approach will result in a consistent and quantitatively accurate volume of condensate production volumes. Novel/Additive Information An innovative quantitative approach to the accurate estimation of condensate volumes originating in the gas cap - but produced from wells completed in the oil rim zone - has been developed and validated and could be applied for other fields, in addition it is fully flexible for future enhancements if needed. This methodology will definitely save time and unnecessary discussion and will provide more consistent results that will lead to more consensus from different parties.

Computing power is still the limiting factor in photorealistic real-time rendering. Foveated rendering improves perceived quality by focusing the rendering effort on where the user is looking at. Applying foveated rendering to real-time path tracing where we must work on a very small number of samples per pixel introduces additional challenges; the rendering result is thoroughly noisy and sparse in the periphery. In this paper we demonstrate foveated real-time path tracing system and propose a novel Visual-Polar space in which both real-time path tracing and denoising is done before mapping to screen space. When path tracing a regular grid of samples in Visual-Polar space, the screen space sample distribution follows the human visual acuity model, making both the rendering and denoising 2:5x faster with similar perceived quality. In addition, when using Visual- Polar space, primary rays stay more coherent, leading to improved utilization of the GPU resources and, therefore, making ray traversal 1.3 - 1.5x faster. Moreover, Visual-Polar space improves 1 sample per pixel denoising quality in the fovea. We show that Visual-Polar based path tracing enables real-time rendering for contemporary virtual reality devices even without dedicated ray tracing hardware acceleration.

Mitigating the effects of head-of-line blocking (HoLB) was one of the major reasons the IETF SIGTRAN working group developed SCTP, a new transport protocol for PSTN signaling traffic, in the first place. However, studies of the impact of HoLB blocking on TCP and SCTP have given ambiguous results as to whether HoLB has, in fact, any significantly deteriorating effect on transmission delay. To this end, we have carried out a detailed experimental study on the quantitative effects of HoLB. Our study suggests that although HoLB could indeed incur a substantial delay penalty on a small fraction of the messages in an SCTP session, it has only a marginal impact on the average end-to-end transmission delay. We only observed improvements in the range of O% to 18% in average message transmission delay of using unordered delivery as compared to ordered delivery. Furthermore, there was a large variability in between different test runs, which often made the impact of HoLB statistically insignificant