Prospects for Sub Sea Wet Gas Compression

Abstract

Wet gas compression technology renders possible new opportunities for future gas/condensate fields by means of sub sea boosting and increased recovery for fields in tail-end production. In the paper arguments for the wet gas compression concept are given. At present no commercial wet gas compressor for the petroleum sector is available. StatoilHydro projects are currently investigating the wet gas compressors suitability to be used and integrated in gas field production. The centrifugal compressor is known as a robust concept and the use is dominant in the oil and gas industry. It has therefore been of specific interest to evaluate its capability of handling wet hydrocarbon fluids. Statoil initiated a wet gas test of a 2.8 MW single-stage compressor in 2003. A full load and pressure test was performed using a mixture of hydrocarbon gas and condensate or water. Results from these tests are presented. A reduction in compressor performance is evident as fluid liquid content is increased. The introduction of wet gas and the use of sub sea solutions make more stringent demands for the compressor corrosion and erosion tolerance. The mechanical stress of the impeller increases when handling wet gas fluids due to an increased mass flow rate. Testing of different impeller materials and coatings has been an important part of the Statoil wet gas compressor development program. Testing of full scale (6–8 MW) sub sea integrated motor-compressors (dry gas centrifugal machines) will begin in 2008. Program sponsor is the A˚sgard Licence in the North Sea and the testing takes place at K-lab, Norway. Shallow water testing of a full scale sub sea compressor station (12.5 MW) will begin in 2010 (2 years testing planned). Program sponsor is the Ormen Lange Licence.

Modelling and Nonlinear Control of a Wet Gas Centrifugal Compressor

“…The fundamental principle of a subsea compression system is the same as that of an equivalent topside compression system, where the main difference is that a subsea compression system is designed to withstand the harsh conditions at the seabed, e.g., higher ambient pressure, corrosion, erosion, etc. [2]. Thus, results presented here can be useful for both subsea and topside facilities.…”

“…The throughput from a producing well increases with increasing pressure difference between the well head pressure and the pressure at the receiving end (back pressure). For small fields, subsea wet gas compression is a cost-efficient boosting technology for increasing the well head pressure and thereby the well throughput to maintain an economically sufficient throughput capable of compressing gases containing up to 5% liquid per volume [1], [2], [3].…”

“…The two types of compressors most useful for gas processing are the axial and the centrifugal compressors, where the centrifugal compressor is dominant because of its high robustness and capacity [2]. The centrifugal compressor casing consists of an inducer section leading the fluid into a rotating impeller section connected to a shaft which increases the fluid velocity.…”

Unveiling the revolutionary role of nanoparticles in the oil and gas field: Unleashing new avenues for enhanced efficiency and productivity

“…If the gaseous substances emanating from the separators have undergone a substantial reduction in pressure, it is advisable to subject them to recompression prior to their transportation [ 300 ]. To enable this feat, turbine compressors consume a mere fraction of the natural gas they compress to generate energy [ 299 ].…”

“…To enable this feat, turbine compressors consume a mere fraction of the natural gas they compress to generate energy [ 299 ]. A centrifugal compressor, equipped with a specific type of fan, can be powered by a turbine to compress and transport natural gas through a pipeline [ 299 , 300 ]. Recompression is deemed unnecessary for gas sourced from a natural gas wellhead, as it possesses sufficient pressure to facilitate its immediate entry into a pipeline transport system.…”