Real-time Horizontal Well Monitoring Systems
Authors: Conn T. 
Published: March 2010

Introduction

With over 12,000 horizontally completed wells on primary production in Canada and many of those (up to 20%) experiencing various production problems, an increased requirement for more accurate bottomhole pressure, temperature and flow data exists. In many horizontal wells, production logging suggests that up to 80% of production comes from only 20% of the horizontal section of the well(s)(l).

As a result, many operators are using or evaluating ways to improve horizontal well productivity in conventional and heavy oil wells. These enhanced oil recovery techniques may include SAGD (stream assisted gravity drainage) and other thermal processes, water flood, and miscible flood schemes.

PROMORE is a technology company that has focused a fiveyear effort on the engineering, manufacturing, and installation of systems that provide continuous real-time pressure, temperature, and flow data associated with horizontal well production.

The company has deployed over 3,000 sensors in various applications using casing conveyed (MOREc), tubing conveyed (MORET) or coil-tubing conveyed (CT-MORE) monitoring systems.

CT-MORE Patent Pending

(Coil Tubing Conveyed) Monitoring System for Horizontal Wells

The latter system (CT-MORE, patent pending), was developed through the cooperation of many operators including the Alberta Energy Company which has utilized many systems for the monitoring of SAGD injector and producer wells for the Foster Creek pilot project (Figures 1 and 3). Based on the success of the pilot project and the value achieved using real-time monitoring, AEC and PROMORE co-patented the CT-MORE.

The value of continuous real-time data in this application cannot be underestimated. SAGD operations and subsequent well designs have been improved through better understanding of the effectiveness of steam injection and placement throughout the horizontal section of the well (Figure 2).

Mobil Oil quantified that real-time operational data was invaluable for the design and drilling of horizontal wells and for the sand containment and control of SAGD producers(2). In addition, the interaction of steam injection with pumping system performance was closely monitored and the data utilized for optimum pump operation.

Another operator determined that the utilization of real-time temperature monitoring was more cost effective and provided better access to data vs. conventional temperature logging.

Conventional logging operations have been determined by several operators to be prohibitively expensive considering the amount of data required and the fact that logging only provides a "snapshot" of the effectiveness of continual process operations.

MOREc (Casing Conveyed) Tool

Horizontal wen drilling and subsequent production operations can also benefit through the use of real-time well monitoring. Typically, a MOREc tool is run as an integral part of the intermediate production casing (Figure 4). Operational pressures during cementing, perforating, fracing, and surge and swap pressures associated with tripping can be monitored on a continuous basis.

Numerous data sets have shown that operators repeatedly cement at pressures exceeding the fracture gradient associated with unconsolidated formations which can adversely effect well productivity.

More importantly pressures during drilling of the horizontal section can be monitored closely and adjustments made to maintain the hydrostatic gradient of drilling fluids and cement can be adjusted proactively to maintain underbalanced conditions (Figure 5).