The SB Field is located in Block PM on the west side of the Malay Basin, Malaysia. It is notorious for its steeply rising pressure ramp, narrow drilling operation window and inter-bedded sand, coal, and shale formations. Block PM is still at the exploration and appraisal stage with limited petrophysical information. Well SBD-2 was the second attempt to reach and cross the F & H sands of this basin. Despite using managed pressure drilling, the first attempt failed when an influx exceeded the fracture gradient, resulting in total fluid losses. Due to the shallow pressure ramp and narrow window between pore pressure and fracture gradient, a repeat attempt was initially deemed "un-drillable". However, the design team felt the target could be reached using an automated managed pressure drilling technology. The team was able to maintain constant bottom hole pressure over three demanding hole sections and reach target total depth. The 8-1/2" × 14-3/4" section required minimum overbalance to manage "wellbore breathing" and to control potential losses to weaker horizons. In the 10-1/2" × 12-1/4" section, the system was used to identify and react quickly to kicks in high pressure sands and also to eliminate wellbore breathing/ballooning. In the final 8-1/2" × 9-1/2" section, the objective was to maintain overbalance in the narrow pressure window between pore pressure and fracture gradient. This paper will describe the design efforts employed while preparing to drill the SBD-2 well. The challenges and lessons learned, particularly managing pore pressure prediction with multiple techniques will be discussed. Lessons learned and recommended workflows for similar projects will also be outlined.

Using a Dynamic Hydraulic and Well Control Simulator to predict and establish wellbore pressures in a narrow margin HPHT well has allowed the operator to set operational limits during drilling, tripping, casing and cementing operations. A previous attempt to reach the objectives for the well failed. A much more rigorous approach to wellbore pressure management was undertaken prior to drilling this second well. A complete review of the expected pressure limitations was conducted, this review included a detailed overview of pore and fracture pressures as well as casing setting depths, hole sizes, temperature effects and proposed mud weights. This resulted in an improved prediction of the pressure windows for each of the proposed hole sections. Each hole section was in turn reviewed for optimal mud weights and this included a detailed review of equivalent static, equivalent circulating and dynamic kick tolerance limitations for the proposed mud weights. Surge and Swab calculations then determined maximum tripping speeds and cementing calculations ensured that pore and fracture pressure limits were not breached with the proposed cement volumes and pump schedules. This paper presents the approach that was taken in proving a complete pressure management system for a narrow margin HPHT exploration well. The use of dynamic hydraulic models allowed accurate predictions of down hole pressures during virtually all drilling operational phases a hole section. Calculated down hole pressures were compared to PWD tools, proving that the accuracy of the dynamic hydraulic predictions was within the required limits to allow drilling without a PWD tool if required. Combining the available pore pressure and fracture pressure data, with mud weight schedules, pump rates, tripping rates and cementing operations allowed optimization of the drilling parameters thus ensuring that this narrow margin HPHT well, was drilled successfully to its target depth and all of its objectives were met.

The HPHT Exploration field is located in Block PM on the Northern side of the Malay Basin, Malaysia, and is notorious for its steeply rising pressure ramp, narrow drilling operation window with only 0.5ppg-0.6ppg in the 14-3/4" and 9-1/2" sections and inter-bedded sand/coal and shale formations Block PM is still at the exploration and appraisal stage and therefore there is limited petrophysical information. Well SBD-2 was the second attempt to reach and cross the F & H sands of this basin. This paper will detail how Formation Pressure While Drilling (FPWD) and Managed Pressure Drilling (MPD) were successfully applied to drill this HPHT exploration well with a very narrow safe mud weight window. FPWD provided a direct pressure measurement while drilling to set the lower boundary and the Dynamic Formation Integrity Tests (FIT) with MPD provided the upper boundary.All the benefits of using a fully automated managed pressure drilling system were necessary to reach Well TD for the first time in this field; including Early Kick Detection (EKD), Dynamic Formation Integrity Tests (FIT), Dynamic Flow Checks and Constant BHP control within a narrow pressure margin.The result of the combined technologies and operational procedures is safely drilling the first successful HPHT well in Malaysia drilled with MPD constant bottomhole pressure application. This well is so far the deepest gas discovery for the north Malay Basin.

The Shearwater field is a deep, high-pressure, high-temperature (HPHT) reservoir located in the UK Central Graben of the North Sea. The current drilling campaign represents the first round of well re-entries into the field following a campaign of slot recoveries to facilitate sidetrack development opportunities.A high level of reservoir depletion (Ͼ 8000 psi) has resulted in significant changes to the drilling envelope that has added complexity to the drilling practices required to successfully exploit the remaining reserves.Managed Pressure Drilling (MPD) Technology was pursued as an enabling technology to navigate within some very narrow margins in the first well of the redevelopment campaign. MPD was implemented in conjunction with drill-in liner and wellbore strengthening technologies to successfully deliver this first well and prove the techniques required to prolong field life.To promote successful implementation of MPD in the target zone, the technology was employed in the previous hole section to gain experience with the equipment and procedures where pressure control was less critical.MPD was used to control bottom hole pressure to manage background gas and facilitate changes to equivalent mud weight. It was further used to minimise the effects of loss/gain mechanisms and enable drilling through a tight margin between pore and fracture pressure while reducing the risk of borehole instability and losses. The technology was also used to determine appropriate mud weights for tripping and provide trip margin to avoid swabbing while tripping. In addition, MPD was used to facilitate cementing in tight margins. This paper will highlight the multiple uses of MPD throughout the start-up of this current drilling campaign and key learnings enabling successful implementation of a new technology on the rig. Shearwater OverviewShearwater is a HPHT gas condensate field discovered in 1988 and located in the UK Central Graben of the North Sea. Primary production is from the Fulmar -a sandstone reservoir with virgin pressure of 15,400 psi and temperatures Ͼ 360°F. MPD Objectives by Hole Section ¼؆ Hole Section to Top Cromer KnollMPD was not planned as a requirement for this hole section. The primary objective for MPD in the 12 ¼Љ hole was to gain experience and shakedown the equipment, rig-up configuration and procedures on a rig using MPD for the first time.Although not a primary objective, MPD could also provide enhanced kick detection capability in the event of higher than expected pressures (especially through the Hod Mass Flows -discrete layers of hard, low porosity chalk interbedded with marls within the Hod formation and commonly associated with high background gas levels while drilling), loss detection capability in the event of lower than expected pressures and the ability to test the drilling window through dynamic pore pressure and FIT/LOT tests.MPD could also be used to allow a lower mud weight to facilitate identification of the pressure ramp in the Tor and promote faster rates of penetration through the chal...