A 5-stage helico-axial multiphase pump was tested for studying its performance. The multiphase pump was tested on the conditions of different speed and different gas volume fraction (GVF). According to the test result, performances of the pump were analyzed. And the effects of speed and GVF to differential pressure and efficiency as well as to power of the pump were analyzed at the same time, so some conclusions were made basing of the above research and some of them are very helpful for the future application on the oilfield.

The challenges facing the subsea production system are becoming increasingly complex with hydrocarbon production moves into deep and even ultra-deep waters. As the most critical equipments, subsea trees need to be designed synchronously against the increasing technology gaps. This paper highlights the common considerations for subsea trees design, especially the horizontal Xmas tree, towards future deepwater application, and the main contents consists of structure design combined with subsea seal technology and the important thermal design in terms of insulation materials selection and application, numerical simulation. Meanwhile, some suggestions and application cases are also included in this paper.

Deadleg is a kind of blind pipe connected with a main pipe used for fluid transportation, which has distinct flow characteristics. This work aims to investigate the complex flow, oil/water separation and the relation between fluid flow and water concentration of a vertical deadleg. The investigation was based on the solution of algebraic slip mixture model, which calculated the continuity and momentum equations for the mixture of oil and water, and solved the volume fraction equation for the secondary phase. The computed results indicated that the mixing zone of the deadleg consists of two circulation vortexes and the whole mixing length depends on the inlet flow intensity. Furthermore, distinct oil/water stratification forms in the stagnant zone, and the maximum water volumetric concentration is related to the length of stagnant zone and also influenced by the flow intensity of the main pipe, which could increase from 25% to 72% with inlet velocity ranges from 0.75m/s to 5m/s.