Geostar

A real-time, computerized version of the basic two-man mudlogging unit. The computer adds to the efficiency of the mudlogging crew while providing error-free calculation in lag, penetration rate and a host of other parameters.

Equipment and Services

Basic package

·   &n 929f521j bsp;   &n 929f521j bsp; Computer

·   &n 929f521j bsp;   &n 929f521j bsp; Depth panel

·   &n 929f521j bsp;   &n 929f521j bsp; Pump & Log Stroke panel

·   &n 929f521j bsp;   &n 929f521j bsp; Automatic Chromatograph

·   &n 929f521j bsp;   &n 929f521j bsp; Hotwire gas detector

·   &n 929f521j bsp;   &n 929f521j bsp; Thermal gas detector

·   &n 929f521j bsp;   &n 929f521j bsp; Mud temperature out

·   &n 929f521j bsp;   &n 929f521j bsp; Weight on bit & hook load

·   &n 929f521j bsp;   &n 929f521j bsp; Computerized parameter alarms

·   &n 929f521j bsp;   &n 929f521j bsp; Unit pusher and logger

·   &n 929f521j bsp;   &n 929f521j bsp; One wet or dry cuttings sample

·   &n 929f521j bsp;   &n 929f521j bsp; Properties of drilling fluid

·   &n 929f521j bsp;   &n 929f521j bsp; 1-inch mud log

·   &n 929f521j bsp;   &n 929f521j bsp; 5-inch mud log in shows

·   &n 929f521j bsp;   &n 929f521j bsp; Show evaluation

·   &n 929f521j bsp;   &n 929f521j bsp; Connection and trip gases

·   &n 929f521j bsp;   &n 929f521j bsp; Penetration rate (feet per hour)

·   &n 929f521j bsp;   &n 929f521j bsp; Three copies of daily and final logs

·   &n 929f521j bsp;   &n 929f521j bsp; Pressure package includes a 1-inch log with the following:

·   &n 929f521j bsp;   &n 929f521j bsp; Drilling porosity

·   &n 929f521j bsp;   &n 929f521j bsp; Dc exponent

·   &n 929f521j bsp;   &n 929f521j bsp; Estimated pore pressure

·   &n 929f521j bsp;   &n 929f521j bsp; Mud weight in

·   &n 929f521j bsp;   &n 929f521j bsp; Mud out temperature

Optional features

·   &n 929f521j bsp;   &n 929f521j bsp; Remote monitor for company man

·   &n 929f521j bsp;   &n 929f521j bsp; Extra men; two sample catchers are required at high rates of penetration

·   &n 929f521j bsp;   &n 929f521j bsp; Extra sample; no charge if there are extra men on location

·   &n 929f521j bsp;   &n 929f521j bsp; Geostar log drawing; computer-drawn logs on-line and real time

·   &n 929f521j bsp;   &n 929f521j bsp; 1-inch TVD mudlog; can be swapped for any log in basic package at no extra cost

·   &n 929f521j bsp;   &n 929f521j bsp; Full 5-inch mudlog; can be swapped for any log in basic package at extra cost

·   &n 929f521j bsp;   &n 929f521j bsp; Hydrogen-sulfide detector; one-channel sensitive to one-fifth part-per-million

·   &n 929f521j bsp;   &n 929f521j bsp; F.I.D. chromatograph

·   &n 929f521j bsp;   &n 929f521j bsp; Fax machine; Internal fax included in log drawing

·   &n 929f521j bsp;   &n 929f521j bsp; Engineers or user-defined log

·   &n 929f521j bsp;   &n 929f521j bsp; Rig floor monitor; Black&white monitor only

·   &n 929f521j bsp;   &n 929f521j bsp; Shale density; non-toxic heavy solution compound

·   &n 929f521j bsp;   &n 929f521j bsp; Infrared gas detector with carbon dioxide; used where hotwires get fouled by special mud additives or the mud itself is sensitive to carbon dioxide

·   &n 929f521j bsp;   &n 929f521j bsp; Pump pressure

·   &n 929f521j bsp;   &n 929f521j bsp; Rotary RPM

·   &n 929f521j bsp;   &n 929f521j bsp; Rotary torque

·   &n 929f521j bsp;   &n 929f521j bsp; Chloride monitor

·   &n 929f521j bsp;   &n 929f521j bsp; Flow

·   &n 929f521j bsp;   &n 929f521j bsp; Pit level system

DATALOG

GEOSCIENCES DIVISION

Mud Logging Services

Mud Logging provides subsurface geological information while drilling a well.

Mud Logging is the examination and analysis of geological information contained in formation cuttings and drilling mud to determine if oil and gas are encountered during drilling a well. Mud Logging also is used to provide critical safety functions such as determining pore pressures, kick control and ambient gas monitoring. Mud Logging is used while drilling most exploratory and many development wells, both onshore and offshore.

Mud Logging services range from cost effective basic unmanned gas detection to sophisticated full service manned Mud Logging.

Mud Logging services also have evolved to include acting as the information center for the well and may include the electronic monitoring of drilling parameters (such as weight on bit, torque, penetration rate, mud levels, pump speed, etc.) and third party service provider data.

Basic unmanned Mud Logging utilizes a cost effective unit that provides simple gas detection to aid in identifying potentially productive pay zones and enhancing drilling safety. The systems can be configured for hydrogen sulfide ("H2S") monitoring. The units record a log of the data and drilling penetration rates and also have alarms that may be set to alert the user of gas increases and equipment problems.
Advanced drilling monitoring systems are capable of providing gas detection as well as sophisticated electronic monitoring and database recording of a full range of drilling parameters on a manned or unmanned basis.

Manned Mud Logging provides experienced crews and additional tools to monitor and analyze both the geology of the subsurface formation as well as the drilling parameters.

Manned Mud Logging can include various combinations of services and crew sizes, depending on the customer's requirements and the complexity of the well.

Manned Mud Logging is conducted in a portable laboratory ("Mud Logging unit") that houses the Mud Logging hardware and software (Mud Logging system).

The Mud Logging analysis is conducted at the wellsite during the drilling process and samples are returned to the operator after analysis.

Gas Detection

Analyse Hydrocarbon Gases in less than 30 seconds!

Datalog's gas chromatograph is the most important and useful tool used in the identification, evaluation and interpretation of hydrocarbons. Hydrocarbon shows are often missed or poorly evaluated because of the
speed restrictions of conventional chromatographs.

By incorporating the highspeed chromatograph, Datalog has virtually eliminated the fear of missing bypassed pay and poorly defined zones of interest.

Benefits:

. Precise Identification of Pay Zones
. Determination of Oil/Gas/Water Contacts
. Geosteer Horizontal wells
. Prediction of Reservoir approach

The sample injection system is made up of reliable silicon components that have been tested to more than 2.5 million cycles without signs of wear, and over 15 million times without failure.

Pore Pressure Prediction

Accurate prediction of pore pressures and fracture gradients has become almost essential to drilling deep wells with higher-than-normal pore pressures.

Costs and drilling problems can be reduced substantially by recognizing abnormally high pore pressures early. The accurate determination of fracture gradients defines the need for protective casing that must be placed on total annulus pressures during drilling.

Every method used to recognize or predict changes in pore pressure is based on formation compaction or the lack of it. Compaction occurs primarily in shales; hence, most prediction methods are based on what happens when drilling or logging shale sections, and shale becomes denser as depth increases. If shale does not become denser as depth increases, suspect abnormally high pore pressures.

Pore pressure transmission also can be described as the transmission of mud overbalance pressure by penetration of the mud filtrate into the rock micropores and fractures. This transmission of mud overbalance pressure to the rock weakens the rock matrix, but more importantly, effectively removes the differential pressure between the mud and the rock, causing hole instability.

Recognizing changes in pore pressure while drilling is vital so that mud weight can be altered before problems develop. Decreases in pore pressure may signal lower fracture gradients and a high vulnerability to underground blowout. Increases in pore pressure, if not contained by quick increases in mud weight, may result in difficult-to-control well kicks and subsequent blowouts.

BP has developed new technologies to monitor the wellbore pressure in real-time. The operator can determine the pore pressure and fracture gradient in real time from logging-while-drilling (LWD) measurements and managing the wellbore pressures between these limits.

Two recent deepwater Gulf of Mexico wells have benefited from real-time wellbore pressure management at the wellsite. The advantages of having a good handle on the pore pressure and fracture gradient while drilling in deepwater include:

Safety;

Avoiding time lost and cost due to kicks and losses;

Pushing casing seats as deep as possible to eliminate additional casing or liner strings

Improved average rate of penetration by avoiding unnecessary flow and bottoms-up checks; and

Increased chance of reaching deep exploration targets

Real-time pore pressure

Wellbore pressure management is reliant on an accurate determination of pore pressure. BP, during normal drilling operations, provides predrill pore pressure predictions based on analysis of seismic velocities, offset well data and basin modeling. However, predrill estimates are, by their nature, uncertain. Limitations include:

Low resolution of seismic interval velocities

Questionable accuracy of depth of events ahead of the bit; and

Uncertainty in the seismic velocity to pressure transformation

The inherent uncertainties in predrill predictions can be addressed by interpreting LWD logs in real time. The sonic and Resistivity measurements can be used (together with a gamma ray) to perform a pore pressure analysis.

Essentially, this means the drilling team can monitor the pore pressure right behind the bit 24 hours a day. Using this technology, the drilling team can gain more value from LWD measurements, and it can use the data to support important drilling decisions. In situations where the pore pressure model shows a significant change, the interpretation skills of the onshore experts can be called upon. Collaboration between the onsite engineer and the onshore pore pressure specialist is vital.

Real-time fracture gradient

The upper limit to the wellbore pressure management window generally receives less attention than the pore pressure but is equally important. Pore pressure is a significant input to the fracture-gradient calculation. As pore pressure is being computed in real time, so too is the fracture gradient. The onsite engineer computes sand and shale fracturing gradients. Shale fracture gradients can be calibrated to leak-off pressures, which are measured accurately with downhole pressure gauges. In addition, recent work with multiple depth of investigation Resistivity tools has started to reveal a mass of information about fracturing and fluid loss in the wellbore in both sands and shales. This is essential information the onsite engineer is well positioned to make good use of to calibrate fracture gradient models.

Additional monitoring: In addition to the LWD and measurement-while-drilling measurements, the onsite engineer integrates all other indicators of pressure. These tend to be indicators Mud-loggers traditionally have monitored, such as background and connection gas, cuttings and cavings, rate of penetration and torque, mud losses and gains. Onsite engineers work closely with the Mud-loggers, shaker hands, drillers, the drilling engineer and the company man to obtain as much pressure-related information as possible. Armed with this information, the engineer acts as a focal point for information and decision support, which in turn can provide good wellbore pressure management.