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West Virginia
Abstract Influenced by the success of shale gas production worldwide and to meet requirements for clean energy supply, a multidisciplinary team of petroleum specialists was established in Saudi Aramco. Meeting the growing requirement in industrial consumption and especially electricity production is driving force for developing unconventional gas reserves. "The initial focus is in the northwest and in the area of Ghawar, where gas infrastructure exists. Initial knowledge building from similar plays in North America is being supplemented with internal technical studies and research programs to help solve geological and engineering challenges unique to Saudi Arabia and to locate specific wells planned for 2011. The company is innovatively combining knowledge and research to maximize gas reserves and production from conventional and unconventional resources in order to meet growing domestic demand." [1] During years 2010 โ 2011 major international petroleum industry players โ Schlumberger, Halliburton and Baker Hughes โ were invited to share their experience in a series of workshops held in Dhahran. Exchange of expert ideas developed into appreciation of complexity of the shale gas reservoir and helped to identify the scope of work for the first Silurian Qusaiba shale gas well. The SHALE-1 well was drilled in 2007 as a gas exploration well. Recent drilling and geophysical data obtained in the well were beneficial for detailed sidetrack and fracture stimulation design. The Multidisciplinary Saudi Aramco - Halliburton SHALE-1 task group was established and positioned in Dhahran. This allowed them to have regular face-to-face meetings and improve the most critical criteria of any new venture โ communication. The draft work plan was developed 8 months before actual operations commenced on the well site. Thorough examination of the draft work plan progressed to the final work plan with a number of improvements. For example, "R" Nipples were dropped from the monobore 4-1/2" completion string. The Frac Stimulation design was fine-tuned, involving expertise from Saudi Aramco and Halliburton. The Complete Well on Paper exercise involved over 25 specialists from both sides and helped to rectify remaining completion/stimulation design issues, and put everyone on the same page in terms of the work program. Well site operations commenced in May 2011; the well was successfully re-entered and window cut in 7" liner. An S-shaped 5โ7/8" hole was drilled in the direction of minimum horizontal stresses, to the required depth in Qusaiba Shale with a maximum DLS of 4ยฐ. The well was completed with 4-1/2" cemented liner and monobore 4-1/2" string to surface. The Hot Qusaiba interval was perforated; frac stimulated with mixed results and successfully flowed. A temporary isolation FasDrill plug was set above the perforation interval. The Warm Qusaiba interval was perforated; successfully frac stimulated and flowed with mixed results. Finally, the FasDrill plug was drilled out with CTU and both intervals flowed and required production log runs. All targets set for the SHALE-1 re-entry well were successfully achieved and the well was suspended for future utilization as an observation well.
- Government > Regional Government > Asia Government > Middle East Government > Saudi Arabia Government (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- North America > United States > Texas > Permian Basin > Midland Basin > Kingdom Field > Abo Reef Formation (0.97)
- North America > United States > Texas > Permian Basin > Midland Basin > Kingdom Field > Abo Formation (0.97)
- North America > United States > West Virginia > Appalachian Basin > Marcellus Field > Marcellus Shale Formation (0.94)
- (9 more...)
Abstract During the past six years, the technology for shale gas/oil developments in North America has seen many improvements and optimizations as the industry experiences a sharp rise in the contribution of hydrocarbons from these resources. More recently, Europe and Australia have joined the US in expanding recoverable hydrocarbons from these unconventional resources, and initial activities are on the rise in Latin America, China, Saudi Arabia and India. Despite such improvements and optimizations, a closer look at the performance reveals that not all wells are producing commercially. In addition, the hydraulic fracture stages are not all contributing within the producing wells. This scenario potentially suggests that it is important to target the field's sweet spots while dealing with shale resources (like most other hydrocarbon-bearing formations). Hence, resource development based on the current concepts of geometric placement of hydraulic fracture stages (e.g., using fixed well/fracture spacing) may not be appropriate to develop such heterogeneous unconventional resource basins. In the discussion we illustrate certain well-defined criteria that can identify the sweet spot locations within a field/basin for the optimal well placement. We further document the vital formation/zone characteristics that define the locations for hydraulic fracture stages and thus move away from the arbitrary geometric placement. The paper will discuss the well-placement optimization process and identify the required combination of proposed special petrophysical, geochemical, and geomechanical investigations (wireline, Logging While Drilling and cores). The hydraulic fracture stage placement analysis as presented, shoulders on the need to understand the existing natural fracture system. This understanding is achieved through geophysical log measurements and comprehensive analysis of the hydraulic fracture development pattern, as well as interaction of hydraulic fractures at each stage with the natural fractures. A naturally fractured reservoir can be drained more efficiently if a complex fracture network can be created by the hydraulic fracture stimulation. This begins by drilling the well in the direction of minimum principle horizontal stress in the area. The paper concludes by presenting examples demonstrating the practical application of some of the specific aspects of the methodology discussed and with a number of specific conclusions. In summary, the three key points to Proper Placement of Wells and Hydraulic Fracture Stages, in order to maximize the net value of an operator's asset are: Begin With a Complete Understanding of the Reservoir Use a Multidiscipline and Integrated Approach Across Each Phase of the Life Cycle Effectively Use Modern Technology
- North America > United States > Texas (1.00)
- Asia > Middle East (1.00)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Geological Subdiscipline > Geochemistry (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.96)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play (0.94)
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Seismic Surveying > Passive Seismic Surveying > Microseismic Surveying (0.68)
- North America > United States > Texas > West Gulf Coast Tertiary Basin > Eagle Ford Shale Formation (0.99)
- North America > United States > Texas > Sabinas - Rio Grande Basin > Eagle Ford Shale Formation (0.99)
- North America > United States > Texas > Maverick Basin > Eagle Ford Shale Formation (0.99)
- (10 more...)
Copyright 2012, Society of Petroleum Engineers This paper was prepared for presentation at the SPE Canadian Unconventional Resources Conference held in Calgary, Alberta, Canada, 30 October-1 November 2012. This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Contents of the paper have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Electronic reproduction, distribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of SPE copyright. Abstract A proliferation of massive new resource rock (shale) gas fields has come on-stream in the past several years. This has significantly increased gas production and, along with an economic slowdown globally, these factors have combined to create a gas glut in North America and a corresponding fall of gas prices. The industry response to these very low prices has been to reduce the number of rigs drilling for gas; many have been redeployed to several promising new (or reinvented) liquids producing "shale" fields, including gas shales making condensate, as well as traditional very low permeability oil formations. The development of a new completion approach quickly transformed the low-permeability sector of gas and oil well completions--drill a long (flat and straight) lateral section through the heart of the reservoir and then complete with transverse hydraulic fracture stimulations at several points along the lateral, just as if each point (perforation set) were an independent vertical well location (i.e., the Shale Completion Model). The industry also adopted as its primary horizontal completion technique a process called "perf-and-plug," in which pumpdown plugs are used with attached multifire perforating guns. At least three and often up to seven separate intervals are perforated and simultaneously fracture stimulated, adding potential challenges to effectively place proppant into all fractures and achieve or maintain near-wellbore (NWB) conductivity. Today's drilling is now focusing on liquids plays, which make effective fracture conductivity far more important. The ways in which more conductivity can be delivered need to be revisited, be it with additives, proppant selection, or design approach. This paper reviews fracturing state-of-the-art methods for ultralow-permeability liquids-producing reservoirs and shows how fracture conductivity and economic optimization can be better achieved.
- North America > United States > Texas (1.00)
- North America > Canada > Alberta > Census Division No. 6 > Calgary Metropolitan Region > Calgary (0.24)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.97)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play > Shale Gas Play (0.68)
- North America > United States > West Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Texas > West Gulf Coast Tertiary Basin > Eagle Ford Shale Formation (0.99)
- (44 more...)
Abstract Northern Mexico has the first major non-associated gas producer basin in the country. However, unconventional reservoirs (mostly very low-permeability shale gas and oil formations) have not been produced so far in this area. These types of reservoirs are located in sedimentary environments where rocks have a high organic-rich content that, when subjected to pressure and temperature conditions, transform this matter into oil and gas. Stimulating a source rock is relatively a new phenomenon in the oil and gas industry. Because these source rock formations have very low permeability, massive hydraulic fracturing stimulation treatments are required to produce at economical rates. Experience and knowledge in drilling and completing wells in this type of reservoir have increased in the last decade. New technologies to evaluate this type of formation and post-production studies have significantly improved, offering better completion methods and techniques. The Eagle Ford formation in Mexico is located in the northern portion of the country and is considered an extension of the Eagle Ford formation that crosses southern Texas in the United States; during June 2011, production from this US formation was 636 MMscf/D and 97,000 bbl/D. For the completion of this subject well, which was drilled horizontally, the evaluation techniques, completion plan, and stimulation design were performed using local experience acquired in unconventional reservoirs (tight oil and tight gas) along with experience from the US in shale gas and oil shale formations. This work shows how this type of formation was identified through several studies, completion was designed and executed, and the fracture treatments were optimized, as well as production matching and forecasting results. This was all performed in the context of an operation that had never been performed in Mexico.
- North America > United States > Texas (1.00)
- North America > Mexico (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (1.00)
- Geology > Geological Subdiscipline (1.00)
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Seismic Surveying (0.93)
- North America > United States > Texas > West Gulf Coast Tertiary Basin > Eagle Ford Shale Formation (0.99)
- North America > United States > Texas > Sabinas - Rio Grande Basin > Eagle Ford Shale Formation (0.99)
- North America > United States > Texas > Maverick Basin > Eagle Ford Shale Formation (0.99)
- (9 more...)
Abstract The Eagle Ford shale is a hydrocarbon-producing formation of significant importance due to its capability for producing at high-liquid/gas ratios, more so than other traditional shale plays. Situated in south Texas, the total Eagle Ford liquids production in 2007 was less than 21,000 bbl total. In 2011, production averaged 65,500 BOPD in the play (EIA, 2011). Activity in the Eagle Ford continues to increase because the benefits from producing high liquid yields across much of the play, along with attractive commodity prices, have made the Eagle Ford a more attractive development over many other shale reservoirs. The rapid development of the Eagle Ford shale was enabled by horizontal drilling. In 2007 none of the reported production was from horizontal wells. In 2011 alone over 2,800 drilling permits were issued, virtually all of them for horizontal wells (RigData, 2012). The Eagle Ford shale has low-clay content, high-carbonate content, and is in an extensional basin, making it conducive to somewhat complex hydraulic fracturing (Martin et al, 2011). The plug and perforating technique has become the preferred completion method in the play due to multiple entry points creating complex fractures at a minimal cost. This completion technique requires a mechanical means for conveying perforating guns, such as coiled tubing (CT), wireline tractor or stick pipe, for the first fracturing stage at the toe of the well. To streamline their completion process, an Eagle Ford operator chose to use an initiator valve that is run at the toe of the well as part of the final completion design. This pressure activated valve is capable of initiating operations on the first fracturing stage without the need for CT or other mechanical means of conveyance of perforating guns. Simple and robust, the valve is activated by a pressure increase from the surface. The valve uses a rupture disc for precise activation and a helical port design that allows for hydraulic fracturing to be performed through the valve into the cement and the formation. With over a dozen wells completed in the Eagle Ford formation by the operator, the valve has provided logistical and economic benefits to the streamlined completion process. This paper describes the initiator valve completion tool and its application in the Eagle Ford shale. A case history is presented to show the specific design and operation of the initiator valve, as well as its benefits over other completion practices that target the first stage in a closed lateral system. Detailed activation of the valve and fracturing data through the valve are also presented.
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (1.00)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Government > Regional Government > North America Government > United States Government (0.55)
- North America > United States > Texas > West Gulf Coast Tertiary Basin > Eagle Ford Shale Formation (0.99)
- North America > United States > Texas > Sabinas - Rio Grande Basin > Eagle Ford Shale Formation (0.99)
- North America > United States > Texas > Maverick Basin > Eagle Ford Shale Formation (0.99)
- (24 more...)
Abstract Multistage hydraulic fracturing is one of the key technologies affording the successful development of unconventional reservoirs. Transverse fracturing of horizontal wells has become the standard for development of these plays, allowing commercial exploitation of what were once considered uneconomic resources. The primary goal of the completion in these ultra-low permeability formations is to provide a conductive path to as much rock as possible, through the use of multistage hydraulic fractures along a horizontal lateral. This requires two separate, yet complimentary strategies โ a wellbore with optimal length and completion hardware, and multiple hydraulic fractures with optimal conductivity. Most completions engineers have a good understanding of their wellbore and completion hardware; however, many do not have the same level of knowledge of their hydraulic fractures. This leads many to incorrectly assume that fracture conductivity is unimportant. However, the fracture provides the critical link between the formation and the wellbore; without a durable fracture, the completion will fail. This paper will present a technique to assess the realistic conductivity of the fracture at downhole conditions, describe the relationship between conductivity and productivity, and evaluate the impact of treatment optimization on economics. Use of this approach allows engineers to design their fracture stimulation to maximize the economic potential of their well. Laboratory data are presented which demonstrate the impact of downhole conditions on proppant performance, including fines migration, elevated temperatures and embedment. In addition, fracture modeling and actual field results will be presented to illustrate the optimization process. Case histories showing the successful implementation of this method will be provided in unconventional gas (Haynesville), a liquids rich formation (Eagle Ford) and an unconventional oil reservoir (Bakken). This paper will serve as a resource to those engineers who wish to gain a better understanding of hydraulic fractures or desire to maximize the economics of their completions in unconventional plays.
- North America > United States > Texas (1.00)
- North America > Canada (1.00)
- Europe (1.00)
- North America > United States > North Dakota (0.93)
- Geology > Geological Subdiscipline (0.88)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play (0.69)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.48)
- North America > United States > Texas > Permian Basin > Yeso Formation (0.99)
- North America > United States > Texas > Permian Basin > Yates Formation (0.99)
- North America > United States > Texas > Permian Basin > Wolfcamp Formation (0.99)
- (40 more...)
Abstract The Marcellus Shale play has attracted much attention in recent years. Our full understanding of the complexities of the flow mechanism in matrix, sorption process and flow behavior in complex fracture system (natural and hydraulic) still has a long way to go in this prolific and hydrocarbon rich formation. In this paper, we present and discuss a novel approach to modeling and history matching of hydrocarbon production from a Marcellus shale asset in southwestern Pennsylvania using advanced data mining & pattern recognition technologies. In this new approach instead of imposing our understanding of the flow mechanism, the impact of multi-stage hydraulic fractures, and the production process on the reservoir model, we allow the production history, well log, and hydraulic fracturing data to force their will on our model and determine its behavior. The uniqueness of this technique is that it incorporates the so-called "hard data" directly into the reservoir model, such that the model can be used to optimize the hydraulic fracture process. The "hard data" refers to field measurements during the hydraulic fracturing process such as fluid and proppant type and amount, injection pressure and rate as well as proppant concentration. The study focuses on part of Marcellus shale including 135 wells with multiple pads, different landing targets, well length and reservoir properties. The full-field history matching process was completed successfully. Artificial Intelligence (AI)-based model proved its capability in capturing the production behavior with acceptable accuracy for individual wells and for the entire field.
- North America > United States > West Virginia (1.00)
- North America > United States > Virginia (1.00)
- North America > United States > Pennsylvania (1.00)
- (3 more...)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (1.00)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play > Shale Gas Play (1.00)
- North America > United States > West Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Texas > Fort Worth Basin (0.99)
- (14 more...)
- Well Completion > Hydraulic Fracturing (1.00)
- Reservoir Description and Dynamics > Unconventional and Complex Reservoirs > Shale gas (1.00)
- Reservoir Description and Dynamics > Reservoir Simulation > History matching (1.00)
- Data Science & Engineering Analytics > Information Management and Systems > Artificial intelligence (1.00)
Optimizing Completion Designs for Horizontal Shale Gas Wells Using Completion Diagnostics
Bartuska, J. E. (J-W Energy Company) | Pechiney, J. J. (ProTechnics Division of Core Laboratories) | Leonard, R. S. (ProTechnics Division of Core Laboratories) | Woodroof, R. A. (ProTechnics Division of Core Laboratories)
Abstract In horizontal shale completions, one of the primary goals is to maximize contact with the most reservoir rock and effectively drain the complex fracture network that has been created during the stimulation process. This paper covers a five-well case study in the Marcellus Shale where completion diagnostics were used to evaluate and optimize the completion process. The case histories will detail key completion parameters and how they changed over time based on various diagnostic results. Completion diagnostics such as proppant and fluid tracers can be integrated with production, stimulation and geologic data to provide useful information as to the effectiveness of the completion design. Proppant tracers have been utilized in horizontal shale basins throughout North America to evaluate near-wellbore fracture initiation, identify un-stimulated perforations, and evaluate proppant interference between stimulated wellbores. Fluid tracers are currently being used to analyze lateral clean-up over time and to quantify fracture fluid interference between wells. In this case study, these diagnostic technologies were instrumental in addressing several completion design questions. Proppant tracers were used to evaluate cluster and stage spacing and also identified proppant interference with adjacent wells. Fluid tracers were utilized to evaluate overall load fluid recoveries for various wellbore trajectories and helped quantify the source and amount of interference between wells.
- North America > United States > West Virginia (1.00)
- North America > United States > Pennsylvania (1.00)
- North America > United States > Virginia (0.90)
- (2 more...)
- North America > United States > West Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Tennessee > Appalachian Basin (0.99)
- (9 more...)
Abstract Determining the optimal number of wells for infill drilling in an unconventional reservoir is a critical endeavor for shale gas operators as many leases are held only by production. To develop a given section, operators must select locations and completion designs for all wells. The planned well placement and completion design will dictate the economic viability and production of the field for the asset's life. The key factors impacting performance in shale gas reservoirs can be broadly divided into two categories: controllable and uncontrollable. Uncontrollable factors include rock properties such as porosity, water saturation, net-to-gross, initial pressure, permeability, natural fractures, and fluid properties. Controllable factors related to producibility that can be optimized include well design, completion design, well placement, surface facilities design, and operating conditions. Development schemes must consider both engineering and economic risks that include reduction of reservoir permeability due to rock compaction and changes in completion characteristics/efficiency. To determine optimal development, these factors have to be evaluated. This paper outlines the results of well optimization studies initiated from a production performance analysis of over 100 wells in the Haynesville Shale and over 300 wells in the Marcellus Shale. Both analytical and numerical tools were used in the presented workflow. The study results indicate a threshold of reservoir and completion properties below which any well drilled may be uneconomic based on our financial assumptions. Original gas-in-place (OGIP), rock brittleness, and fracture height containment were considered with regard to stimulated reservoir volume, SRV. The effect of natural fractures was also studied. With low gas prices, optimal capital allocation is a critical development component and is an issue that all operators face. The subsequent results presented could save operators myriad hours of simulation effort while potentially saving millions of dollars by eliminating unnecessary wells.
- North America > United States > Pennsylvania (0.89)
- North America > United States > Texas (0.66)
- Geology > Geological Subdiscipline > Geomechanics (1.00)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (0.88)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play > Shale Gas Play (0.69)
- North America > United States > West Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Texas > Haynesville Shale Formation (0.99)
- (13 more...)
Abstract With estimates of recoverable reserves at approximately 500 Tcf, the Marcellus Shale has become one of the main unconventional shale targets in the U.S. The Marcellus is part of the Appalachian Basin and underlies 95,000 sq. miles of Pennsylvania, New York, Ohio, Maryland, and West Virginia. The Marcellus is a challenging target due to formation characteristics, making it cost-intensive to develop. In addition, operators working in the Marcellus have had to contend with public opposition to hydraulic fracturing, prompting them to look for technologies to make this process more efficient and less resource intensive. This paper compares open hole multistage fracturing systems (OHMS) and cemented casing, "plug and perf" (CCPP) completions and presents the evolution of completion methods utilized in the Marcellus Shale. Production results from horizontal wells in two counties completed with OHMS are compared to offset wells completed with the CCPP method. System details, the fracture methods used, as well as the operational efficiencies of OHMS compared to other horizontal completions methods are discussed. In addition, an update on the recent advances in technologies that have been made since the introduction of OHMS to the Marcellus Shale is presented. Higher cumulative production results at six, 12, and 24 months in both geographic areas of analysis demonstrate the successful application of OHMS systems in the Marcellus Shale. Comparing the two completion methods also highlights the increased efficiency of OHMS systems compared to CCPP. With decreased time and cost requirements, OHMS completions are the clear choice in the Marcellus Shale. Therefore, this paper demonstrates that OHMS technology provides a long-term solution for the life of wells in shale plays. Although the focus is on the Marcellus Shale, principles from this paper can be applied to any unconventional shale reservoir.
- North America > United States > West Virginia (1.00)
- North America > United States > Virginia (1.00)
- North America > United States > Pennsylvania (1.00)
- (3 more...)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock > Mudrock > Shale (1.00)
- Geology > Petroleum Play Type > Unconventional Play > Shale Play > Shale Gas Play (1.00)
- North America > United States > West Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Virginia > Appalachian Basin > Marcellus Shale Formation (0.99)
- North America > United States > Texas > Fort Worth Basin > Barnett Shale Formation (0.99)
- (8 more...)