Download H011194 GeoBalance White Paper PDF

TitleH011194 GeoBalance White Paper
TagsDrilling Rig Oil Well Petroleum Reservoir Fault (Geology) Casing (Borehole)
File Size1.1 MB
Total Pages12
Document Text Contents
Page 1


GeoBalance® MPD Services
Controlling Collapse Pressure

Solving challenges.™

Page 6

Sperry Drilling WHITE PAPER





Managed Pressure Drilling (MPD)

Managed pressure drilling (MPD) is a recent technological improvement that is helping create an

entirely new economic outlook for unlocking unconventional resources. MPD and associated

automation techniques allows operators to improve the economic risk of unconventional assets by

reducing overall drilling and exploitation costs.

Automated Choke.

Rig Pump Diverter

During typical operations in areas of high tectonic stress, wellbore incidents while building the curve

can be encountered, which can result in nonproductive time (NPT) up to several days. ROP

improvement is another primary challenge for operators related to wellbore construction time.

MPD addresses such challenges by allowing the well to be drilled using a closed-loop system. The

closed loop is formed with a rotating control device (RCD) mounted on top of the rig’s annular

blowout preventer (BOP). The sole purpose of the RCD is to safely divert flow away from the rig floor

to the choke manifold. The choke manifold is the pressure regulator of the system.

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Sperry Drilling WHITE PAPER

The chokes deployed with the MPD system can be used in full automation or operated

manually. The choke skid consists of three hydraulic gate seat type chokes in which the trims

can be configured for anticipated flow rates, mud weights, and well pressures. Each choke can

be individually isolated by either pneumatic or manual valves.

Because the choke is the pressure regulator of the closed-loop system, flow across the choke

must be maintained at all times. This is especially true for a well having a narrow margin

between the pore /collapse pressure and fracture gradient.

To maintain the flow across the choke during connection and while tripping, a novel technique

of diverting the flow from the rig’s standpipe to the chokes with a rig pump diverter (RPD) has

been developed. The RPD technology has been implemented in the field for over a year and

has become a key element to the optimization process.

The MPD Process

Before any MPD equipment is mobilized, a fundamental understanding of the drilling environment

must exist. To design the MPD program, a dedicated engineer is assigned to build a hydraulic

pressure profile, create process flow diagrams, valve numbering diagrams, make recommendations

regarding mud weights, design the tripping strategy, build operational procedures, perform a hazard

identification /hazardous operation risk review, and select choke configuration.

Once the equipment is mobilized to the well site, rig crew training is conducted. As the crew becomes

comfortable with the technology, the mud weights and bottomhole pressures (BHP) would be

reduced until there was an indication that the BHP is approaching the pore or collapse pressure.

Once this boundary has been identified, it will become the lower pressure limit for the system.

Conversely, with the MPD system, dynamic leakoff tests or formation integrity tests can be performed

at any time while drilling to ascertain the upper pressure limits.

The following log illustrates the MPD process. The far right column is pressures expressed in mud

weight. The three curves in this track are the actual pressure measured using pressure while drilling

(PWD) (red), the desired control pressure (light blue dotted), and the mud weight (solid blue). The

third track is choke surface pressure given in psi, which is used to control the BHP. The curves in

this track consist of the set points sent to the chokes from the real-time hydraulics model (dashed

black) and the actual choke response (red solid). The second track is a time track with the on bottom

indicator shown in green and in-slips indicator shown in blue. The first track consists of ROP (red

solid) and block position (dashed black).

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Sperry Drilling WHITE PAPER



Resultant temperatures observed within first test well.

The aqua colored trace is the direct offset well’s temperature profile. The light blue is a well

several miles away and up structure, and brown is the test well. Because the goal of the trial

was verification of temperature reduction to prolong LWD life, the temperatures from the three

wells were measured using LWD sensors from the same vendor. The comparison of the first

test well indicated the 1.8-ppg difference in mud weight yielded a 30°F BHCT difference. The

1.8-ppg reduction in mud weight had significant impact on the ROP. The improvement allowed

the well to be control drilled for LWD log quality.

Even with the controlled drilling and relogging section for LWD, the test allowed improved ROP.

When MPD operations began on the test well, it was four days behind the AFE. At TD, the

actual days vs. depth was one day ahead of AFE.

The success of the trials confirmed to the operator that using the MPD technology could allow

other properties to be exploited beyond the temperature limits of current hot hole tools used.

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contract between Halliburton and the customer that is applicable to the sale.
H011194 06/14

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