Use of Pressure Gauges in Liner Running Strings during Liner Cementing Operations

Abstract

fax 01-972-952-9435. AbstractWith surface measurements alone, liner cementing operations are difficult to interpret because of the dampening effects of the mud and greater overlaying pressure events such as cement free fall. In April 2001, an operator in the North Sea started to use downhole memory pressure gauges in the liner running string to gather pressure data for evaluation of liner equipment performance and cement placement. The collected data has shown downhole pressure effects that have not been seen with surface pressure measurements. This data also allows comparison of actual and simulated downhole pressure, which can improve cement job simulations.

Case study of the cementing phase of an observation well at the Pembina Cardium CO2 monitoring pilot, Alberta, Canada

“…However, unforeseen pressure signatures required an explanation. Different factors result in unforeseen pressure signatures, including well influx (migration of native fluid), pumping steps, and multiphase flow and rheology of fluids, which can be modeled using the CEMPRO5 TM approach (Brehme et al, 2003;Piot and Loizzo, 1998). The scope of this section is not to analyze small differences between the simulator and the field data, but to focus the analysis on the major events such as the shut-in period, fluid changeover, and variations in pressure trends.…”