Drilling and Well - Valve usage in changing environment

Abstract

Since the oil price experienced its drastic fall summer 2014, a leaner and more cost effective oil and gas production have been an important element for oil and gas companies. This is why this paper in cooperation with Valvision have investigated valve usage in changing environment with higher demands from operators with regards to cost effective solutions. In order to determine any possible problem areas on Christmas trees (XT) found on oil and gas installations, both qualitative and quantitative research methods have been performed by conducting interviews in the field and XT valves failure rate data gathering from three major oil and gas fields on Norwegian Continental Shelf (NCS). Also the general industry bias when it comes to operator`s willingness to try new valve solution to cut cost have been highlighted by performing interviews with personnel from four different oil and gas installations. To determine any possible improvement areas for valves on XTs, 929 valves found on XTs from three different oil and gas fields have been analyzed. Both failure rates and failure mechanisms have been highlighted and presented to give an overview of possible improvement implementations for valve suppliers. This data has then been compared to the information obtained by conducting interviews with professionals working with XTs on a daily basis, to reflect current situation in the market. The analysis found Choke valves to be the valve type on XT with highest failure rate. These valve were found to have 11.0 % failure rate. This was significantly higher then other valve types found on XT. Valve leakage and corrosion were determined as the failure mechanisms most often occurring for both Choke valves and Gate valves. Also optimization of maintenance procedures for valves on XTs were highlighted, as it was observed lack of optimal procedures within workers performing maintenance on these valves. The importance of correct valve material has also been concluded, as many of the failure causes for these valves can be linked to poor valve material choice.