Deepwater Testing Basic Awareness Training Material Testing Services © 2010 Schlumberger All rights reserved An asterisk is used throughout this presentation to denote a mark of Schlumberger Other company, product, and service names are the properties of their respective owners Objectives: Deepwater Testing Basic Awareness To provide basic understanding and awareness of common technical subject matter related to deepwater exploration, appraisal and development activities This includes: What is Deepwater Testing? Deepwater Rigs Heave Compensation Systems Variable Deck Loading Station Keeping – Moored and DP Deepwater Risers and BOPs Basic Subsea Trees Basic Met Ocean Subsea Landing Strings What is Deepwater Testing? We define a deepwater operations as any Testing activity on a floating MODU (Modular Offshore Drilling Unit) Floating MODU: ● Moored vessel (e.g Semi-submersible) ● Dynamically Positioned vessel (e.g drillship) Testing activity: ● Operational activity executed on that vessel by one, some, or all of the Testing Sub-segments What is Deepwater Testing? Deepwater Deepwater Deepwater What is Deepwater Testing: Subsea LS Definition Depth of water ● Deepwater > 1000ft (300m); ● Ultra-deep water > 5000ft (1500m) Rig Type – Floaters ● drillship ● semi-submersible What is different in Deepwater? The following differences may apply to deepwater well construction: Increased water depth Increased operating pressures and temperatures downhole Subsea equipment requirements Surface facility requirements Wellbore stability and/or quality Production and flow assurance (e.g hydrates) New generation of drilling, testing, and completion challenges Operating environment (Met Ocean) New generation of technical professionals required How is a Deepwater Rig Different It floats! Vessel which features mooring/station keeping capability Utilizes rig heave compensation system Variable deck loading (VDL) considerations due to rig motion BOPs are on the sea-bed Extended marine riser systems to access the sea-bed and well Significantly increased operating costs and client exposure Significantly increased impact of non-productive time “Deepwater is Our Reputation” The associated cost of NPT in deepwater operations is severe The customer must minimize risk, despite increased operational costs Schlumberger must provide reliability through excellence in execution in deepwater operations High costs = high exposure Service quality incidents will attract considerable attention and have an increased impact on our reputation 10 Deepwater Riser Systems: SS BOPs The purpose of the subsea BOP system is: Shut in the well as needed Allow for rig movement Allow temporary suspension and re-entry (in the event the rig must move of station quickly) Provide an integral connection to the well and sea floor (i.e subsea well-head) Provide multiple redundant methods of shutting-in and isolating the well 28 Deepwater Riser Systems: SS BOPs Features include: Increased capacity for increased variation in ram sizes (multiple DP sizes) and multiple Variable Bore Rams (VBRs) Sometimes two annular preventers feature in the BOP stack often with increased closing force to account for riser hydrostatic opening force Pipe rams feature the capability to support the weight of the drill string so that it can be hung-off and the well isolated in the event the rig must move off station quickly Two sets of shearing rams – conventional blind shearing rams (sealing) and casing shearing rams (non sealing) 29 Deepwater Riser Systems: SS LMRP The Lower Marine Riser Package: ● Located directly above the BOP stack ● Features the ability to disconnect from the BOPs ● Features a flex joint to allow some rig movement without loading the BOPs directly connected to the subsea wellhead on the seabed The Flex Joint: ● Can provide up to ten degrees of tilt in any direction ● Available in different working pressures and tensile ratings 30 Deepwater Riser Systems: Drilling Riser The Drilling Riser Is the “tube” between the LRMP and rig, provides conduit for the drill-string and drill fluids from the well and sea-bed back to the rig Wall thickness and tubing grade depends on water depth due to increasing collapse loads at deeper water depths Increasing depth requires higher wall thickness and grade Most DW risers utilize flanged riser connections Significant weight, increasing with water depth, which must be supported by the rig Buoyancy units are attached to each riser section to reduce the weight of the string in water 31 Deepwater Riser Systems: Telescoping Riser Joint The Telescopic Riser Joint Also known as the riser “slip-joint” Located in the top section of the drilling riser Permits relative movement between the stationary section of the drilling riser (which is attached to the sea-bed) and the upper section which is attached to the moving drilling rig Consists of a hydraulic or pneumatic activated packing element Provides “termination point” for the riser tensioning system Riser tensioner ring Shown stroked in 32 Deepwater Riser Systems: Marine Riser Tensioner The Marine Riser Tensioner Tensioning system which maintains positive pulling force on the drilling riser independent of the movement of the rig This counteracts high forces which can be transmitted to the riser due to rig movement Consists of a number of riser tension lines attached from the rig to the marine riser (at the load ring on the riser slip joint) Hydraulic system – a cylinder with sheaves at each end for the tension line The wire rope tension line is fixed to the rig and through the sheaves The other end is connected to the riser Line tension is regulated by a cylinder and piston connected to high pressure gas bottles and a low pressure accumulator 33 Deepwater Riser Systems: Diverter The Diverter Located immediately below the rig floor, above the riser slip joint The diverter provides a means of diverting an unexpected release of well fluids (primarily gas) to a location away from the rig floor at the extremities of the rig 34 Subsea Trees There are two categories of subsea production trees: Vertical Trees Horizontal Trees 35 Subsea Trees: Vertical Vertical Subsea Trees Tubing hanger landed in the well-head before deploying tree Tree valves stacked vertically on top of the tubing hanger “Vertical” flow path of produced fluids through the TH and SST with vertical master valve orientation Downhole functions for the completion via hydraulic/electronic penetrations through the bottom of the tree to the top of the tubing hanger The tree must be pulled in order to recover and rerun completion strings 36 Subsea Trees: Horizontal Horizontal Subsea Trees Tree deployed before the completion and tubing hanger Completion is deployed through the horizontal production tree Tree cap installed after installation of completion is complete “Horizontal” flow path of produced fluid through tubing hanger and tree Fluid flows through production port in side of tubing hanger aligned with flow-line in tree Horizontal orientation of master valve Downhole functions provided through radial penetrators on the side of the tubing hanger Completion strings can be recovered without pulling the tree 37 Met Ocean “Metocean” ● A combination of the words "Meteorology" and "Oceanography" The term is used to describe the offshore physical operating environment of a MODU or offshore structure (platform) As water depth increases, environmental loading on a rig increases (increased winds, higher seas, ocean currents etc) Environmental loads impacting a floating rig include: ● Wind – typically collinear with seas, highest load on a semi, drillships aim to orientate bow into the wind usually ● Waves – can be highest environmental load in extreme locations, drillships have increased sensitivity ● Currents – winds generate a shallow surface current, deeper currents generated by earth rotation Can impact drilling riser 38 What happens if… The rig loses station while testing or has to move quickly in the middle of a well-testing operation? 39 Subsea Landing Strings Subsea Landing String (SenTREE) provides a fast acting and reliable means to: Isolate the landing string from the test string Prevent discharge of landing string content (retainer valve) Disconnect the landing string from the test string / completion Provide additional barriers in the flow path Pump through feature Cuts wire line & coil tubing 40 Schlumberger SSLS products Subsea safety systems ● SenTREE (3.0” Bore – Exploration) ● SenTREE (7.0” Bore – Development/Completions) ● SenTREE HP (High Pressure Operations) Subsea control Systems ● Direct Hydraulic Mid-water control System ● SenTREE Electohydraulic deepwater control system ● SenTREE Commander deep-water control system ● SenTREE / HP SenTURIAN Deep-water control system Good luck with the Deep Water Basic certification quiz in iLearn 42 ... or all of the Testing Sub-segments What is Deepwater Testing? Deepwater Deepwater Deepwater What is Deepwater Testing: Subsea LS Definition Depth of water ● Deepwater > 1000ft (300m); ● Ultra-deep... their respective owners Objectives: Deepwater Testing Basic Awareness To provide basic understanding and awareness of common technical subject matter related to deepwater exploration, appraisal... What is Deepwater Testing? Deepwater Rigs Heave Compensation Systems Variable Deck Loading Station Keeping – Moored and DP Deepwater Risers and BOPs Basic Subsea Trees Basic Met Ocean