The Upper Devonian-Lower Mississippian Bakken petroleum system, including the Bakken, Lower Lodgepole, and Upper Three Forks formations, is a widespread unit within the central and deeper portions of the Williston Basin in Montana, North Dakota, and the Canadian provinces of Saskatchewan and Manitoba. The USGS estimated that the U.S. portion of the Bakken Formation contains between 3 and 4.3 billion barrels of undiscovered, recoverable oil, 1.85 Tcf of associated/dissolved natural gas and 148 million barrels of natural gas liquid; the Upper Three Forks Formation is estimated to contain 20 billion barrels of oil, with approximately 2 billion barrels of recoverable oil.
There are extensive horizontal drilling and multi-stage hydraulic fracturing activities targeting these two formations. Those horizontal wells typically have 10,000 ft lateral sections in pay zones and multi-stage hydraulic fracturing with 24 to 36 stages. The extensive well paths bring numerous challenges, including precisely landing the curve, enhancing drilling rig operating conditions to obtain measuring while drilling (MWD) system optimal performance, and avoiding drilling into undesirable formations. Overlooking some or all of these conditions could lead to unnecessary high dogleg severity (DLS), poor rate of penetration (ROP), unnecessary trips and sidetracks to name a few. All these conditions could ultimately add additional time and cost to the drilling and completion program of the well and in the worst-case lower future production rates to the operator.
Several practical field techniques and technology applications are presented as solutions to help optimize ROP, reduce non-productive rig time and chances of sidetracks. Several field examples were analyzed. The techniques gained are valuable for developing optimal drilling practice procedures, and improving drilling operations and future well production.
Pearse, Chris (BP Exploration Co Ltd) | Adams, Nicola (BP Exploration Operating Company Ltd) | Bateman, Philip (BP Exploration Co Ltd) | Bouska, Jack G (BP Middle East Region) | Duque, Carlos (BP Exploration Co Ltd) | Gravestock, Martyn (BP Exploration Co Ltd) | Stone, Johnathan (BP Exploration Co Ltd)
In January 2010 BP Exploration Jordan Ltd signed an agreement with the Hashemite Kingdom of Jordan and the National Petroleum Company (NPC) to explore and appraise the 7,200 sq km Risha Concession. The concession, in the desert of Eastern Jordan, bordering Iraq, Syria and Saudi Arabia contains the partially developed Risha Gas Field. This has historically been a poor seismic data quality area, mostly due to a complex and variably karstified near-surface. There was a sparse coverage of heritage 2D lines and two 3D surveys covering just 5% of the concession and a strong need for a large areal coverage of improved quality 3D seismic data. New and cost-effective techniques in acquisition and processing have been deployed to address the seismic coverage and quality issues, and during 2010 to 2012, a ~5000 sq km Simultaneous Source Seismic (DS3) survey was acquired and processed. The high-density wide-azimuth acquisition was carried out in a time and cost-efficient way. Following innovative acquisition and processing techniques to address the extreme scattered noise problem, high quality seismic attribute products have allowed insights into lithology and potential fracture distribution for the first time in the area. In this paper we discuss the acquisition, processing and analysis that have allowed the data quality improvement and the impact on reservoir interpretation.
Every operation site, oil and gas drilling, shipping , pipelines and loadingfacilities, need a design basis to be properly planned. Also monitoring of theenvironment when the operation has already started is of utmost importance.This became noticed already in late 1960ies during the Manhattan voyages. Eversince ice data has been collected around various projects both in the westernand eastern Arctic. In Canada the heat was on during the Polar Gas and ArcticPilot Project in the 1970ies and 80ies. The discoveries in the Russian Arcticlaunched systematic arrangements to collect ice data in the in thePechora Sea, Barents Sea, Kara Sea, Ob Bay and offshore Sakhalin Island duringthe last 25 years. This paper describes the main features of typicalarrangements made for a successful data collection expedition, how arrangementsworked and also difficulties met during the execution of such anexpedition.
Poedjono, Benny (Schlumberger) | Beck, Nathan (Schlumberger) | Buchanan, Andrew (Eni Petroleum Co.) | Brink, Jason (Eni Petroleum Co.) | Longo, Joseph (Eni Petroleum Co.) | Finn, Carol A. (U.S. Geological Survey) | Worthington, E. William (U.S. Geological Survey)
Geomagnetic referencing is becoming an increasingly attractive alternativeto north-seeking gyroscopic surveys to achieve the precise wellbore positioningessential for success in today's complex drilling programs. However, thegreater magnitude of variations in the geomagnetic environment at higherlatitudes makes the application of geomagnetic referencing in those areas morechallenging.
Precise, real-time data on those variations from relatively nearby magneticobservatories can be crucial to achieving the required accuracy, butconstructing and operating an observatory in these often harsh environmentsposes a number of significant challenges. Operational since March 2010, theDeadhorse Magnetic Observatory (DED), located in Deadhorse, Alaska, was createdthrough collaboration between the United States Geological Survey (USGS) and aleading oilfield services supply company. DED was designed to produce real-timegeomagnetic data at the required level of accuracy, and to do so reliably underthe extreme temperatures and harsh weather conditions often experienced in thearea.
The observatory will serve a number of key scientific communities as well asthe oilfield drilling industry, and has already played a vital role in thesuccess of several commercial ventures in the area, providing essential,accurate data while offering significant cost and time savings, compared withtraditional surveying techniques.
There are many challenges associated with the design and installation ofArctic subsea pipeline. A leading example is the Northstar developmentpipelines currently operating safely offshore the Alaskan North Slope. Uniqueoffshore Arctic environmental loading conditions, such as ice gouging,influence each pipeline design differently. Statistical distributions andprobabilistic assessments of ice gouge records can be used to predict designextreme gouge depths which can then be used to determine pipeline burial depthsrequired for protection against ice keels.
The Northstar subsea pipeline project used the statistical ice gougeanalysis method described by Lanan et al. (1986), based on the exponentialprobability distribution, to select design pipeline burial depths forprotection against ice gouging. This method was applied to publicly availabledata and site-specific survey data collected prior to the pipeline installationin 2000, to predict the design extreme ice gouge depths expected along thepipeline route. Each year since the pipeline installation, new ice gouge datahas been collected by BP Exploration (Alaska).
This paper reviews additional ice gouge data collected since installation ofthe Northstar pipelines and has assessed the use of alternate ice gougeanalysis methods to predict extreme ice gouge design depths for future pipelineinstallations in the Beaufort Sea, Data available from all Alaskan Beaufort Seaice gouge surveys in the Northstar pipeline area was also included in some ofthe statistical comparisons.
Results obtained using the exponential analysis method were compared toanalyses using alternate probability distribution functions (PDFs), such as theWeibull, gamma, and log-normal. Data thresholds have also been investigated forPDF fitting. Work by Caines (2009, 2011) has shown that alternate probabilitydistribution functions might be more appropriate for modeling ice gouge depthdata, compared to the traditional exponential method. A brief comparativeanalysis was conducted using known age Northstar pipeline route data toinvestigate the effects of using all available gouge depth data versus annualmaximums only.
A three year cycle is generally needed to adequately plan, execute, processand interpret a medium size 2D or 3D seismic program in the Canadian Arctic.The tasks of designing, supervising and monitoring the seismic surveys isdivided between the oil and gas exploration company, a seismic managementcompany and a seismic contractor well experienced in Canadian Arcticacquisition. In order to complete these seismic programs, MGM Energy Corp.dedicated extensive efforts and manpower to mitigate environmentalconsiderations within the survey area while respecting federal, territorial andlocal regulations and maintaining good and productive relationships developedwith the area's first nations and northern groups. A series of "Best PracticeMeasures", based on the extensive northern work knowledge and expertise of MGM,its contractors and the local communities, were adopted in the successfulcompletion of these projects.
Respecting federal, territorial and local regulations and maintainingproductive relationships with the area's First Nations is required in allphases of program implementation. For MGM "Best Practice" in Arctic seismicacquisition means permanently innovating and improving on the set ofenvironmental, safety and technical policies and conventions which are currentin seismic data acquisition in various Arctic physiographic and geologicalsettings.
Extensive airborne electromagnetic (EM) ice thickness surveys have beenperformed in April 2009, 2011, and 2012 over the Canadian Beaufort Sea with along-range airplane. These are contributing to the Beaufort RegionalEnvironmental Assessment (BREA) project which gathers ice information inpreparation of a regulatory framework for safe and environmental responsibleoil and gas production. Results show that the location of the multiyear iceedge can be very variable from year to year. Multiyear ice modal thicknessesranged between 3.0 and 3.7 m. The seasonal ice zone had very variable icethicknesses depending on the amount and age of ice formed in coastal polynyasand leads throughout the winter. However, we gathered enough data to show thatmodal first-year ice thicknesses of 2.0 to 2.2 m emerge if profiles are longenough, which can be considered the most representative first-year icethickness estimate in the Canadian Beaufort Sea in April. However, in theseasonal ice zone also regions with heavily deformed ice thicker than 10 m, andoccasional multiyear hummock fields of similar thicknesses occur. Resultssuggest that multiyear hummock fields may not comprise the thickest ice as theyare affected by melt during the summer. Two ice islands had thicknesses between20 and 30 m. Our results suggest a melt rate of ice islands of 10 m per year inthe Southern Beaufort Sea. Ice thickness surveys were complemented by theanalysis of satellite radar data and tracking of ice features by means of GPSbeacons. We demonstrate that all these activities combined comprise a powerfultool for a future Arctic sea ice environmental observatory.
There is a growing interest in seismic surveys in arctic areas. Normally 2Dsurveys can be carried out with limited risk, as long as the area is reasonablyfree of ice. However, 3D seismic surveys are an essential tool for explorationin order to de-risk prospective areas ahead of expensive and challengingdrilling operations. Acquisition of 3D surveys, with multiple streamers, is farmore difficult than single streamer 2D surveys, as the amount of in-seaequipment is an order of magnitude higher and the data density for a given areacovered is far greater: the physical footprint of a 3D equipment spread beingtowed behind a vessel can be about a kilometer wide by several kilometers long.This significantly increases the risk of equipment damage due to ice. Thispaper summarizes experiences from several 3D surveys in the Arctic, andaddresses how the use of new equipment and techniques can reduce such risks toacceptable levels.
Management - No abstract available.
We introduce a 3D ocean bottom cable (OBC) seismic survey design flow with the so-called focal beam method for finding the optimum acquisition geometry to satisfy geophysical requirements. This method is based on the so-called common focus point (CFP) technology, and it is a subsurface oriented and target oriented approach, making it possible to quantitatively analyze sought-after attributes, such as potential resolution and pre-stack amplitude fidelity, for one or more gridpoints in the subsurface of a given acquisition geometry.
We implemented the survey design flow offshore Abu Dhabi with several acquisition geometries to understand the effects of essential survey parameters, like 4D spatial sampling intervals with and without symmetric sampling, aspect ratio, roll pattern and wave type to be recorded, on the sought-after attributes. Summarizing these results, the relationship between essential survey parameters and resulting data quality was well understood.