Use of Distributed Temperature Sensors and Permanent Gauges in Shallow Wells to Monitor Real Time Fluid Movement to the Surface and Within the Well Bore

Abstract

Abstract In the recent past four shallow wells were drilled in the Ahmadi Area and the purpose of these wells was to observe the fluid movement in these wells, either to the surface or communication between the zones in the down-hole. These unconventional wells were designed for unrestricted inflow of fluids into the wellbore as appreciable commercial flow was never expected. The challenge was also to log the flow and pinpoint the fluid entry points. Conventional PLT tools were not suitable as spinners threshold velocity could not be achieved in such feeble flow. Research was done to find the most suitable tools and equipment that are available in the industry and most useful to this project at very shallow depths and in real-time monitoring. It was decided that the minor temperature variation against the contributing zone could be captured real-time by DTS (Distributed Temperature Sensors) and Permanent Down-hole Gauges will give the real-time pressure and temperature readings at the point of its installation in the wellbore. These data can be analyzed to quantify the flow contribution and fluids entry points. At this shallow depth the effect of diurnal temperature change was also a main factor. The DTS and Permanent Down-hole Gauges were installed in all 4 wells, 3 of these are 250’ deep and the fourth well is 1000’ in depth. The performance of these tools gave very distinctive results that benefitted in the investigation of the fluid movement in these wells and in the surrounding. This paper and presentation will show the details of this project for the 4 wells and the installation and performance of these tools and how it benefitted the project. The real-time monitoring of these data and the challenges encountered will also shared.