Drilling Deep Wells leads to face harsh operational conditions such as HP/HT, wellbore stability issues, narrow influx/losses windows which consequently make these prospects costly inefficient and highly risky safety wise, especially if the case is an exploratory well. Managed Pressure Drilling (MPD) is an enhancement of the primary well control provided by the utilization of a closed and pressurizable circulating system for the drilling fluids (mud), this enables drilling with precise management of the wellbore pressure profile, aiming to optimize drilling processes by decreasing nonproductive time (NPT), mitigating drilling hazards and to enable the drilling of otherwise technically or economically un-drillable and high-complexity prospects, offering a considerable amount of tangible benefits. Because MPD addresses NPT, the technology is of greatest potential benefit to deep wells drilling programs where cost of dealing with troublesome zones while drilling is much higher.

Several wells ranking from appraisal to wildcat exploratory with considerable pore pressure unknowns, coupled with narrow pore-fracture drilling window characteristic of HPHT conditions have been already drilled under the MPD technology in the MENA region. MPD was able to minimize the problems faced on previous wells conventionally drilled, by enabling various techniques which include the use of pressure build up analysis to quantify formation pressures, the application of dynamic flow checks, dynamic formation strength limits, and the application of constant bottom hole pressure during dynamic (pumps-on) and static (pumps-off) drilling fluid conditions. There are different providers at diverse levels of complexity that approach MPD systems. The system mostly selected by the operators to drill deep wells consists of an automated surface choke control system based on the mass balance monitoring principle and Rotating Control Device (RCD). The advantages of an automated MPD system are related to a quick reaction to the expected drilling problems and formations pressures uncertainties, all linked with the drilling process of an exploratory deep well. Drilling-related issues such as excessive mud cost, slow rate of penetration (ROP), wellbore ballooning/breathing, kick-detection limitations, difficulty in avoiding gross overbalance conditions, differentially stuck pipe, twist-offs, and resulting well-control issues contribute to the decision of applying the MPD technology. This presentation summarizes the application of MPD to address drilling hazards by drilling with more precise wellbore pressure management utilizing an automated MPD system based on flow balance monitoring, adding value to the conventional drilling practice.

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