Abstract This study presents experimental results and techniques that are developed for measuring in-situ cuttings concentration using nuclear densitometers under dynamic conditions. One of the key problems in borehole hydraulics and cuttings transport is the determination of in-situ cuttings concentration in the borehole while drilling. In order to investigate cuttings transport efficiency with aerated fluids under elevated pressure and temperature conditions, in-situ cuttings concentrations were measured manually (i.e. by flushing out the cuttings into a container and weighing them) and using nuclear densitometers. In-situ cuttings concentrations that were obtained using these two different measuring methods are compared and discussed. The results show good agreement between densitometer readings and cuttings weight measurements. This study is useful for designing in-line monitoring systems that accurately measure the cuttings concentration in drilling applications.

A discussion about horizontal foam flow behavior in pipes and annular geometry under elevated pressures and temperatures is presented. The study is empirically based and covers the effects of foam quality, foam texture, pressure, temperature and geometry of the conduit on the rheological response of

The Quarter began with installing the new drill pipe, hooking up the new hydraulic power unit, completing the pipe rotation system (Task 4 has been completed), and making the SWACO choke operational. Detailed design and procurement work is proceeding on a system to elevate the drill-string section. The prototype Foam Generator Cell has been completed by Temco and delivered. Work is currently underway to calibrate the system. Literature review and preliminary model development for cuttings transportation with polymer foam under EPET conditions are in progress. Preparations for preliminary cuttings transport experiments with polymer foam have been completed. Two nuclear densitometers were re-calibrated. Drill pipe rotation system was tested up to 250 RPM. Water flow tests were conducted while rotating the drill pipe up to 100 RPM. The accuracy of weight measurements for cuttings in the annulus was evaluated. Additional modifications of the cuttings collection system are being considered in order to obtain the desired accurate measurement of cuttings weight in the annular test section. Cutting transport experiments with aerated fluids are being conducted at EPET, and analyses of the collected data are in progress. The printed circuit board is functioning with acceptable noise level to measure cuttings concentration at static condition using ultrasonic method. We were able to conduct several tests using a standard low pass filter to eliminate high frequency noise. We tested to verify that we can distinguish between different depths of sand in a static bed of sand. We tested with water, air and a mix of the two mediums. Major modifications to the DTF have almost been completed. A stop-flow cell is being designed for the DTF, the ACTF and Foam Generator/Viscometer which will allow us to capture bubble images without the need for ultra fast shutter speeds or microsecond flash system.

This is the second quarterly progress report for Year-4 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between October 1, 2002 and December 30, 2002. This report presents a review of progress on the following specific tasks. (a) Design and development of an Advanced Cuttings Transport Facility Task 3: Addition of a Cuttings Injection/Separation System, Task 4: Addition of a Pipe Rotation System. (b) New research project (Task 9b): ''Development of a Foam Generator/Viscometer for Elevated Pressure and Elevated Temperature (EPET) Conditions''. (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions''. (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings. (Task 12), and Viscosity of Foam under EPET (Task 9b). (f) New Research project (Task 13): ''Study of Cuttings Transport with Foam under Elevated Pressure and Temperature Conditions''. (g) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (h) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

Abstract A review of foam and aerated drilling fluid technology is presented. The review includes an analysis of foam and aerated fluid rheology and flow-pressure loss models. Problems associated with the applications of current models are discussed. Suggestions for possible model modifications and needs for future research are offered. Recently, a new research initiative has been undertaken by the University of Tulsa to build an Advanced Cuttings Transport Facility (ACTF). Development and utilization of the ACTF will offer the industry an insight into the complex processes that govern fluid flow during drilling and production phases. The basic construction of the facility is in progress. The facility will eventually allow investigation of cuttings transport with incompressible and compressible drilling fluids at elevated temperature (200 °F) and elevated pressure (2000 psi). The design aspects of the ACTF and the scope of the project are discussed in the present paper.