Abstract
High-angle wells with longer and longer departures are being drilled at an ever-increasing pace on the North Slope of Alaska and around the world. This type well is used to penetrate new oil reservoirs and increase oil recovery in older maturing oil fields. The older maturing oil fields are being waterflooded with gas reinjection to maintain reservoir pressure, which results in wells that produce oil with high water cuts and high gas-oil ratios. These complex downhole production profiles create a difficult production logging environment.
A totally new logging tool is being used to determine the production profile when a high-angle well is producing oil with high water cut and high gas-oil ratios. This compact tool directly measures water holdup and gas holdup distribution around the wellbore, along with velocity data and X-Y caliper all 18 in. above the bottom of the tool. Pressure, temperature, inclination, with gamma ray and casing collar locator, are also included in this compact tool. All measurements can be run with an electric line unit or in memory mode. The memory mode eliminates the need for electric line when logging horizontal wells or wells that have high surface flowing pressures.
Sigma/porosity and carbon-oxygen measurements can be combined with this short production logging tool, when run on electric line, so that the production profile and the reservoir behind the casing can be evaluated on a single trip into the well. The combination of the production profile and formation evaluation is then used to determine how to produce the well and manage the reservoir to maximize oil production and recovery.
Production profiles from four different wells demonstrate the value of these direct measurements and how they were used in planning the remedial work to increase oil production and reduce or eliminate unwanted gas and water production.
