Real-Time Monitoring and Control of Water Influx to a Horizontal Well Using Advanced Completion Equipped with Permanent Sensors

Abstract

We have tested new technologies for real-time monitoring and control of water influx to horizontal wells with sand control completions. We drilled a horizontal well in a thin oil column in Indiana, which was completed openhole with sand screens and a gravel pack. External casing packers subdivide the annulus into three zones. An electrical valve, which also records the annular and tubing pressure, controls inflow to each zone. Twenty-one centralizers act as electrodes to form a resistivity array that spans the 694-ft-long completion. The well is also equipped with a fiber-optic-distributed temperature sensing system. The well has been produced since November 2001 and provides real-time data that are shared across a geographically distributed network and used to optimize the production of oil from the well. The data from the pressure sensors and the resistivity array have been jointly interpreted to dynamically update the static reservoir model, which was initially based on observations in offset vertical wells. The pressures recorded from the three electrical valves provide high-frequency data to characterize the near-well heterogeneity of the formation. This is critical to computing an optimum production strategy. Zonal well tests, combined with interference testing between zones and wells, allow for estimation of communication between zones and the productivity index of each zone. The resistivity data enable detection of water saturation changes both in the formation and in the wellbore. The completion technology tested in this well offers the potential to intelligently operate long horizontal sand control completions by combining real-time monitoring with downhole inflow control. Introduction The production performance and ultimate recovery of horizontal wells are often less than predicted by fluid flow simulations. Premature breakthrough of water or gas to the wellbore, caused by uneven influx along the well, is one reason for this disappointing performance. We tested a variety of sensing technologies that facilitate the intelligent operation of remotely operated valves to maximize well productivity and ultimate recovery of oil. To achieve this test, we installed a completion in a very thin (originally 13-ft thick) oil column in the East Mount Vernon Unit of the Lamott Consolidated Field, Posey County, Indiana (Fig. 1). This unit is operated by Team Energy and produces oil from the Tar Springs and Cypress sandstones. Most production is from the Mississippian Cypress sandstone reservoir. The previously existing vertical wells produce at a very high water cut (approximately 95%) because of the thin nature of the Cypress reservoir oil column.