Combining Pressurised Mud Cap Drilling (PMCD) and Early Kick Detection (EKD) Techniques for Fractured Formations Overlying a High Pressure Reservoir in Offshore Kalimantan

Abstract

Pressurized Mud Cap Drilling (PMCD) and Early Kick Detection (EKD) are two unconventional drilling techniques that have been used widely individually, mostly in relation to closed and pressurizable systems and to Managed Pressure Drilling (MPD) applications. However, both techniques are seldom used together as an integrated setup. This paper describes a synergized PMCD and EKD setup and field deployment that was used to successfully drill a well in offshore Kalimantan, Indonesia that had a high pressure formation below a zone prone to severe circulation losses. The key components in the setup were a rotating control device (RCD) and a Coriolis mass flow meter. Using an RCD, the drilling system was converted from a conventional open-to-the-atmosphere to a closed-loop system that allows more precise diversion and accurate well flow monitoring, when used in conjunction with a Coriolis mass flow meter. Since it is a closed system, the comparison of the flow coming out of the well with the flow pumped into the well will provide advance information regarding any influx or outflux from the system. The system designed also takes into consideration the efficiency in switching between modes, that is, from conventional drilling to PMCD mode or to EKD mode and then, back to conventional mode. Possible improvements to the system and equipment are also discussed in the paper, as well as how the current system was utilized to successfully drill a well that previously involved multiple sidetracks when attempting to drill conventionally to target depth.

Transient Open‐Closed Loop Experimental Validation of a Nonlinear Two‐Phase Flow Distributed System

“…[4,38,39,73] It constitutes a two-phase flow model, comprising conservation equations of liquid-gas phases and a conservation equation of the mixture momentum, considering isothermal flow and neglecting mass transfer between the phases. The set of equations are described as exposed on Equations (1)(2)(3).…”

“…The majority of world oil reserves are located in carbonate reservoirs, which are characterized as a drilling challenge due to its complexity and heterogeneity nature, presenting strongly fractured and karstified zones, leading to drilling scenarios of large or even total losses of the drilling fluid, also facing gas kick disturbances. [1] International Association of Drilling Contractors (IADC) defines the technology named MPD (Managed Pressure Drilling) as "an adaptive drilling process, used to precisely control the annular pressure profile throughout the wellbore. The objectives are to ascertain the downhole pressure environment limits and to manage the annular hydraulic pressure profile accordingly".…”

“…The majority of world oil reserves are located in carbonate reservoirs, which are characterized as a drilling challenge due to its complexity and heterogeneity nature, presenting strongly fractured and karstified zones, leading to drilling scenarios of large or even total losses of the drilling fluid, also facing gas kick disturbances. [ 1 ]…”

Bullheading optimization study of the PMCD technique

“…PMCD technology (Fig. 1) is a variation of Managed Pressure Drilling (MPD) that feeds a light annular mud (LAM) in the top of the annulus region, while a sacrificial fluid (usually sea water) is pumped through the drill string, in order to carry the drill cuttings not to the surface, but, instead, to the formation (Jayah et al 2013;Benny et al 2013). As a matter of fact, seawater carries the drill cuttings to the formation for sealing fractures.…”