Mar 21, 2017 casing design overview overall process of how to do casing design in oil and gas industry casing design objectives. Water well basics a water well is a hole, shaft, or excavation used for the purpose of extracting ground water from the subsurface. If you are not an engineer, and many casing strings are designed by nonengineers, do not be discouraged by the many equations you see. There are three major requirements to be considered in designing production casing. Agree the well objectives, schedule, costs, order equipment, place contracts for the rig and services, prepare the site. Understanding casing design in the traditional way is important so that computer generated mistakes are averted. A method used to increase driving depth is to utilize an. Hetrick slide 7 of 22 surface casing is cemented and tested cement is the primary barrier for vertical migration of fluids into usdws the first attempt aka primary cement job. An upper exterior casing screen segment that is installed within the upper aquifer zone. Casing path well design a casing path well is designed to allow for concurrent production from a shallow aquifer and depth aquifer.
Semidetailed look at drilling a well 7 identifying a target. A small diameter surface casing is set inside the conductor casing and extends beneath the deepest freshwater zone to protect it from contamination. Understanding well construction and surface footprint. Well design and well integrity wabamun area co s project. Well design and abandonment of wells in the wabamun lake area ercb, 2007. To isolate porous media with different fluidpressure regimes. The program includes a database of over 48 different joints of casing to choose from plus the option to add custom csg specs. The items below are design objectives for well constructions which drilling. Casing path well an effective method to deal with cascading water. The basics of wells how is an oil or gas well built. Usually about 5 ft of well hole is drilled between bailing. When considering to install and utilize a dug well as a water supply one must understand if the. The presentation discusses casing design factors and casing design loads. A guide to water well casing and screen selection cover.
Keep septic systems, fertilizers, gasoline, fuel oil, and chemicals away from your well page 30. Casing design the following topics will be discussed functions of casing casing types casing specifications casing design bending effects buoyancy effects shock loads functions of casing to keep the hole open and to provide a support for weak, or fractured formations. If you continue browsing the site, you agree to the use of cookies on this website. The first four chapters contain the main bulk of the book. True vertical depth tvd is now fully linked to vertical well geometry or directional well geometry. Design is based on the maximum mud weight at the casing depth 53.
However, casings and screens alone comprise the principal substance of a completed water well. Dug well design wells constructed by excavation dug wells, or wells installed by excavation, can be a viable source of water when installed and maintained properly. Different types of wells and the status of a well gives rise to different leakage scenarios. Casing design user manual page 3 1 well data before proceeding with the casing design, the well profile must be established. The casing string design program for windows, casing2, has been. Check the casing design s sensitivity to these doglegs by running a casing wear model. The information provided drives much of the equipment selection. Casing design user manual page 1 drillingsoftware casing design user manual 1.
Feb 14, 2018 introduction and api standards of casing choosing the correct size, type, and amount of casing that is used in well construction is of utmost importance to the success of the well. Burst design assume no backup fluid on the outside of the casing. Collapse design assume that the casing is empty on the inside, that is, no pressure inside the casing and no buoyancy effect. In consolidated formations, no casing is required for drilling. Steel rubber spring design to absorb torsional and vertical vibration placed normally above the bit stabilization requirement dictate placement 30 to 50 above the bit drill string design design means determination of length, weight, grades of drill pipe to. Depth and diameter values on the yaxis correspond to the final well bore architecture shown in figure 22. Ensure well casing joints have adequate strength to carry the weight of casing throughout. Considerations in site selection include the location of existing water towers, storage. The intent is to drill the wells to a total depth of 25003000 m, with slotted 7 liners run to the bottom. Theory and practice is a very useful book for all drilling engineers, especially the ones who are involved in well planning and design. Due to the plastic loading conditions and nonlinear material response, fea is often used to assist in the design of well tubulars in conjunction with a strainbased design methodology. The second constraint occurs if the vacuum is lost by air entering the well line through leakage at the wddwgb14 dug well design wells constructed by excavation. The book is divided into six wellorganized chapters.
The durability and efficiency of a well depend to a large degree on its design, construction procedures and selection of casing and well screen. Steel casing specifications comparison michigan department of environmental quality well construction unit astm a53 astm a106 astm a589 api 5l manufacture open hearth, electric furnace basic oxygen cast in ingots or strand cast tempering or open hearth, electric furnace, or strand cast open hearth, electric furnace, basic oxygen cast in ingots. Clearly, tubing that is too small restricts production and subsequent economic performance of the well. Tubing that is too large, however, may have an economic impact beyond the cost of the tubing string itself, because the tubing size will influence the overall casing design of the well. It does go into some detail at times, but overall its purpose is to actually teach an understanding of basic casing design. Select build rates to minimise the risk of severe local doglegs while drilling. Well design and engineering integrates all major well design technologies from prespud to td. For example, the mud density plan must be developed before the casing program because mud weights have. Pvc well screen and casing 26 diameter and wall thickness of well casing 26 slots 26 sump 27 pipe joints 27 6. Figure 1 is a typical casing path well design showing its key components, which consist of.
Casing loads in the horizontal well are not different than those developed in conventional well. How to drill a well in five easy steps alex vaughan. Figure 23 the four curves moving from right to left represent overburden stress, fracture gradients in the shale and sands, and pore pressure in the macondo well. Check the casing designs sensitivity to these doglegs by running a casing wear model. It is, if you will, a recipe book for basic casing design. Petroleum engineering, drilling engineering, casing design slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Well design introduction and api standards of casing youtube. This load case applies to wells that experience high pressure. In 1821, william harts first shale gas well near fredonia new york, struck flowing gas at 28 ft. This abstract presents information to consider in the design of a safe and effective production casing string for well production and also as a conduit for a fracture stimulation. Driving the casing enlarges the hole and eventually friction prevents further advancement of the casing. Oct 23, 2014 design is based on the weight of the entire casing string. Wellbore and casing integrity must be suitable for the purpose for which the well is being used.
Wddwgb14 dug well design wells constructed by excavation. Api defines three types of casing weight nominal weight. The straightening process at the mill affects the strength of the casing. The load cases applied to the casing design model are during the production phase. Casing design is linked to well trajectory and azimuth closure. Well design and well integrity the main observation from these studies is that cased wells as more prone to leakage than drilled and abandoned wells, and injection wells are more prone to leakage than producing wells. The casing protects the electrical wires, pull cable and water tubingpiping that are connected to the submersible pump. Monitoring well design and construction for hydrogeologic characterization, guidance manual for groundwater investigations.
How to drill a well in five easy steps alex vaughan, senior drilling engineer. Well test and construction plan prepare and submit a customized well test and construction plan prior to any well drilling activities and include procedures for decommissioning dry wells in the event water is not encountered. Casing design is a completely new concept for biaxial casing design. The drilling team constructs a well design to achieve the well objectives, taking into account the various drilling hazards. Pipe performance is discussed as well as material selection. The well is created by drilling a hole, isolating with casing and cement and repeating this process until the target depth and location are reached. After the well screen, well casing, and gravel pack have been installed, the well is. Case study casing path well an effective method to deal. This test leads to evaluate the success of the cementation, being a fundamental step for structural evaluation of the well casing section. Under these conditions, smaller casing is telescoped inside and drilling continues with a smaller bit. Chapters and 4 are designed to develop a syst,ematic procedure for casing design with particular eniphasis oii deviated. Wabamun area co 2 sequestration project wasp page 6 of 39 well design and well integrity figure 1. In conclusion, rahman and chilingarians casing design. Theory and practice is only one of the two books devoted entirely to casing design.
Figure driven well c pointed drive rod steel casing with beveled end handles to pull casing out of ground after pvc well is inserted pvc well inserted into casing after drive rod. Have any wells that are no longer in use permanently sealed by a licensed well contractor or a licensed well sealing contractor page 31. Water well design and construction thomas harteris uc cooperative extension hydrogeology specialist at the university of california,davis,and kearney agricultural center. Introduction working stress design wsd loads are evaluated throughout the entire length of the casing from the well head to the casing shoe. The engineer responsible for developing the well plan and casing design is faced with a number of tasks that can be briefly characterized. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. If the formation caves, 5 to 10 ft of hole is drilled.
Xie 2006 proposed a casing strain design limit of 1. Casing design considerations for horizontal wells sciencedirect. Slide 19 of 22 casing is cut or perforated near the surface casing shoe. Casing design user manual revision 2 drillingsoftware. Tubing string design while many aspects ofcasing and tubing string design are subject to company prejerences, basic concepts and specific options are presented here. Mention of trade names or commercial products does not constitute endorsement or.
Casing provides support for the wall of the well so that loose rock fragments or unconsolidated sand and gravel through which the well has penetrated do not collapse into the well shaft. Figure 1 is a typical casing path well design showing its key components. It requires that some aspects of the plan be developed before designing other items. A small few are not, and that is one reason that api and iso standards of quality were adopted. The process of selecting pipe typically begins at the bottom of the string, where.
Well design and construction for monitoring groundwater at. Pdf reliability assessment of well casing design based on a. Casing design for horizontal well as well as for conventional wells depends on the loads applied on casing string. Pdf casing design is an important task in oil and gas well design. Production casing is cut, bridge plug is set in the intermediate casing.
All the casings used are grade k55, with threaded couplings. Planning and preparation acquire surface lease agreement determination of multiwell pad or single well pad requirements inform stakeholders of the proposed well construction evaluation of sour gas. To minimize the disadvantages of open hole completion, casing and cementing is to be recommended in horizontal well. An explanation of well efficiency appears in appendix 1. Wellbore integrity of gas storage wells current perspectives. The well design incorporates casing design, drilling fluids, bit and tool selection, and drilling technique to manage drilling hazards. Introduction and api standards of casing choosing the correct size, type, and amount of casing that is used in well construction is of utmost importance to the success of the well. Casing design involves evaluation of the factors that con tribute to the. Usually set in the transition zone below or above pressured formation salt andor caving shale. A typical method for well development is to surge or jet water or air in and out of the well screen openings. The equivalent mud weight emw, expressed in pounds per gallon ppg, must be higher than the. The well design is an input to the well test design. Otherwise, licenses may be cancelled or the well may be suspended. Well design introduction and api standards of casing.
Ensure the wells mechanical integrity by providing a design basis that accounts for all the anticipated loads that can be encountered during the life of the well. The first design task in preparing the well plan is selecting depths that the casing will be run and cemented. Example of possible leakage paths for co 2 in a cased wellbore celia et al, 2004. Pdf reliability assessment of well casing design based. Participants are actively engaged in every aspect of the technical activities required to deliver a costeffective well plan while also gaining valuable perspective on how the overall process should be managed in a dynamic team environment.
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