Abstract
This paper presents a technology designed to obtain the most representative formation samples in minimum time with less contamination. An innovative formation testing technology using the new focused sampling probe and real-time downhole fluid identification service, which enables users to save time and expense by eliminating the need for long pump outs and a second run, particularly in deepwater wells with unconsolidated sand reservoir formations. Representative formation sampling requires minimal differential pressure to move fluid and is uniquely able to provide low-contamination samples in extremely difficult unconsolidated formations. The in-situ fluid ID sensor data, which included fluid density, capacitance, resistivity, pressure, and temperature information, was used in conjunction with contamination forecasting software to provide accurate fluid-contamination predictions.
The formation testing tool "focused sampling probe" delivers a purer fluid sample than the traditional sampling techniques with less pumping time. This decreases uncertainty in terms of establishing connectivity and flow assurance while increasing operational efficiency. The formation sampling service incorporates oval pad geometry with large surface area, resulting in lower forces acting on the formation sandface and reduced sanding. Fluid flow is segmented into an inner and outer flow section; fluids in the outer section will be more contaminated and will be discarded back to the borehole. Fluids in the inner section will be purer and very low contamination is achieved much faster compared to traditional pumpout. In some cases, contamination is too low to be measured. The large flow area of the oval focused pad results in higher flow rate than a circular probe. The fast and versatile pump in the formation sampling service enables reduced cleanup times.
