It also includes adverse financial effects that occur due to extra drilling and casing it requires to run and. Oct 23, 2014 it is imperative to plan for proper selection of casing strings and their setting depths to realise an optimal and safe well at minimal costs. Weatherford personnel was on site to run the liner string that included the centralizer subs. There has been, however, an evident need for more accurate data on the collapse, pullout, and bursting strengths of casing. In onshore areas, the primary role of the surface casing string is to protect freshwater zones and that of the conductor is to raise the mud returns to the.
Jpt digital planning and modeling enhances performance of. Feb, 2017 cdex, pvis casing design software, implements an industryaccepted physics model to perform accurate and practical casing designs for complicated drilling circumstances. For offshore wells, the cement column is frequently limited to the kickoff point. Casing point selection at shallow depth sciencedirect. Support subsequent casing strings, isolate of surface fresh water formation, caseoff unconsolidated or lost circulation areas, on a multi well platform, well may be kicked off in surface hole and surface casing will also protect the build up section common sizes and depth. To determine the setting depth of the next casing, draw a horizontal line bc and then a vertical line cd. The selection of the number of casing strings and their respective setting. Casing point selection network of excellence in training lecture contents. The fivedays course is designed to concentrate on the. Casing setting depth is a crucial part of a well planning procedure. Introduction to casing seating depths design in oil and gas wells. The drag between the casing and the formation in these wellbores often exceeds the hook weight of the casing, which can.
Design factors and comparison between uniaxial and triaxial stress will be evaluated. Surge reduction while running casing can improve well. Special design considerations are required in a number of more complex cases. Lower portions of the string may be assembled with casing of a greater wall thickness to withstand the extreme pressures likely at depth. Severe lost irculation zones are often encountered in the. Selection of casing sizes and setting depths to achieve well objectives. Chapter 1 fundamental aspects of casing design sciencedirect. The methodology was implemented in a microcomputer program written in. Mechanically and chemically optimized cementing systems that benefit from the largest selection of additives in the industry, many of them designed specifically for deepwater. The selection of casing string and setting depth is based on formation pore pressure and fracture gradient of the well. Casing and cementing training course petroskills cac. Some of the issues to address are discussed below and the casing designer will need to check the latest relevant industry experience. For each casing size deployed, casingrunning speeds averaged 7.
Personnel responsible for planning, overseeing, and conducting casing and cementing operations. Selection of fluids for a highlyeffective wellbore conditioning fluid train. Table 2 shows the three scenarios of casing setting depth based on the pressure and temperature survey data from fig. To account for the kick tolerance in the casing shoe setting depth selection, there important data are required. Saltel expandable steel patches are a permanent solution to repair a zone of damaged tubing or casing, shut off unwanted perforations, seal a leaking sliding sleeve, or perform other remedial operations. Chapter 5 casing setting depth selection the first design task in preparing the well plan is selecting depths the casing will be run and cemented. Casing seat selection how to select casing setting depth. Wellcat software is a comprehensive and modular suite of applications that work together to address a wide variety of casing and tubing challenges. Material aspects, connection selection, performance properties, load cases, design factors, and buckling are just a few of the many topics that are covered. The conductor string must be set at a depth that allows circulation of the drilling fluid. This reduces the risk of setting casing strings at unplanned depths, getting pipe.
A short assembly, typically manufactured from a heavy steel collar and profiled cement interior, that is screwed to the bottom of a casing string. Buoyancyassisted casing equipment bace halliburton. The drag between the casing and the formation in these wellbores often exceeds the hook weight of the casing, which can prevent tools from reaching the optimum setting depth. The main reason for setting intermediate casing is to case off the formations that prevent the well from being drilled to the total depth. Database software was developed to assist with queries and data retrieval by the research team. The whipstock setting depth was determined by studying the exact points where the lead mill initiated the cut at each casing string. After analysis of the cases in question, it was found that a casing ovality of 10% at the kop is detrimental for a whipstock operation, while one case showed 5% and were successful. The drilling engineer must consider geological conditions such as formation pressures and fracture gradients, hole problems, internal company policies, and, in many cases, a variety of government regulations. This software allows the user to create multiple design scenarios in order to.
The software simulated how the tools would be run into the open hole, and testing confirmed that they met api 10d standards. Casing setting depth and design of production well in water. The casing string design program for windows, casing2, has been developed jointly by lone star steel company and maurer engineering inc. It is the most important decision made in the preplanning of a well.
The lower portion and sometimes the entirety is typically held in place with cement. The preliminary conclusions are that the 30in casing setting depth is difficult to model, whereas the 20in casing string could be set at shallower depths. Casing point selection network of excellence in training. Setting depth determination on day three, the spreadsheet will be completed with formulas for calculating triaxial stress of various load states which casing may be exposed. It is imperative to plan for proper selection of casing strings and their setting depths to realise an optimal and safe well at minimal costs. The procedure is repeated for other casing strings, usually until a specified surface casing depth is reached. Oct 16, 2017 casing provides locations for the installation of blowout preventers, wellhead equipment, production packers, and production tubing.
Casing equipment that delivers efficiencies while running and landing casing to depth. Long casing strings may require higher strength materials on the upper portion of the string to withstand the string load. Unfortunately, many well plans give significant considerations to the actual pipe design yet give only cursory attention to the setting depth of the pipe. Conductor and surface casing setting depth requirements have evolved from the industrys efforts to provide adequate well control, to protect freshwater zones and to drill at minimum cost. Severe lost irculation zones are often encountered in the interval between 100 and 1,000 ft and are ipes. Casingseat software is deployed on landmarks engineers data model edm technology, the platform for a fully integrated suite of well engineering and data analysis products. Another term for running tool, a generic name for a tool or device that is used in the placement or setting of downhole equipment such as permanent packers or plugs. Chapter 5 casing setting depth selection chapter 5. Casing is a large diameter pipe that is assembled and inserted into a recently drilled section of a borehole. Casing setting depth selection drilling engineering. Expanded with an inflatable packer downhole, the patch creates a highpressure inner lining with minimal loss of diameter. Casingseat software is a graphicsbased tool for accurately determining casing setting depth and viable casing and wellbore schemes. Cdex, pegasus vertexs casing design software, implements an industryaccepted physics model to perform accurate and practical casing designs for complicated drilling circumstances. Many wells have been engineering or economic failures because the casing program specified setting depths too shallow or deep.
The maximum swab depth is calculated and indicated visually for upstrain tension packers if enough fluid is swabbed from the tubing the reduction in hydrostatic pressure can cause the packer to unset. Casing setting depths and depth design concepts will also be covered in detail. Similar to the bones of a spine protecting the spinal cord, casing is set inside the drilled borehole to protect and support the wellstream. Casingseat casing design software landmark solutions. Burst, collapse, tension, compression, bending, buckling and temperature effects are all incorporated into cdex to analyze the casing strings capabilities. All shallower formations must be protected with casing because their respective fracture mud weights are less than the maximum projected requirements 18. Determination of casing setting depth using kick tolerance. Cdex a better and simple way to casing design youtube. The buoyancy was created when an air pocket was trapped between the float shoe on the end of the casing and drillable buoyancyassisted casing equipment bacez assembly located in the casing at a calculated distance from the float shoe. Buoyancyassisted casing equipment bace allows operators to run casing to the bottom of highly deviated or horizontal wellbores. The whipstock simulation software, which calculates dogleg severity for a liner or bha passthrough as well as the stresses of the bha, was used to check the bending moments, ensuring that the completion strings. The large spread in leakoff pressures of the field is further investigated.
The design of a casing program involves the selection of setting depths, casing. The running tool can be retrieved after the operation or setting process. The centralizer subs landed at the setting depth and restored. Using casingseat software in the early phases of the casingdesign process can lead to significant. Stresscheck casing design software enables quick, systematic, and accurate valuation of casing wear limits, and can automatically create the minimum cost design.
Therefore, a distribution range for the minimal setting depth of the conductor pipe can be determined using the statistics data, and by combining its limit setting depth data, a quantitative risk. Setting depths of the surface casing vary from a few hundred feet to as nmch as 5,000 ft. The progress in casing manufacture generally has kept pace with the other phases of drilling, and the maximum depth of drilling is not yet limited by any deficiencies in the properties of the casing. Deepwater wells present two problems for the casing designer, casing setting depth, and environmental loading above the seabed. The depth of intersection,000 ft, is the tentative intermediate casing setting depth. Surface casing depth requirements january 2018 3 alberta energy regulator 2. Chapter 5 casing setting depth selection chapter 5 casing. As an example, for the case with 7 casing setting depth of 3000 meters and effective average rate of penetration in 8. Cdex, pvis casing design software, implements an industryaccepted physics model to perform accurate and practical casing designs for complicated drilling circumstances. Casing provides locations for the installation of blowout preventers, wellhead equipment, production packers, and production tubing. The setting depth and design load case identification of the actual casing were recalculated in this study using the philippines method. The probe is attached to marked tape and mounted on a wellbalanced winding and storage reel. To account for the kick tolerance in the casing shoe setting depth selection, there.
The well casing depth indicator uses a unique but simple magnetic switch device. Many wells have been engineering and economic failures because the casing program specified setting depths too shallow or too deep. Packer calculations 32 bit will help you avoid all the unsetting problems with a visual indication and in the case of compression packers save. With the total depth of a drilling phase set and the formation pressure at that depth known, the shallowest casing setting depth can be established considering the fracture equivalent density curve and pressure inside the wellbore during well control operations.
Registers the depth of each piece of down hole equipment serial numbers, pump ratings, completion depth of motors manufacturers data on all pump units if. Casing points selection initial selection of casing setting depths is based on the pore pressure and fracture pressure gradients for the well. The switch device is housed inside a stainless steel probe 6. Pdf casing setting depth and design of production well in.
An mms database on sustained casing pressure scp was made available for confidential internal use by the lsu research team. Table 2 shows the three scenarios of casing setting depth based on. Drill design simulate fluid flow and heat transfer during drilling operations, for full transient analysis. The cost of casing is a major part of the overall well cost, so the selection of casing size, grade, connectors, and setting depth is a primary engineering and economic consideration.
Result of casing setting depth and design load case identification. Exploration well casing setting depths, development well casing setting depths, exploration versus development same target, restrictions on casing shoe depth, special criteria, example. Actual casing setting depth is checked using a leading commercially available casing design software with a kick tolerance of 10 bbls and 0. To design casing properties to meet burst, collapse, and tensile strength requirements. Programme overview the fundamentals of casing design training programme covers the relevant subjects required to understand the structural mechanics of down hole tubular. The rounded profile helps guide the casing string past any ledges or obstructions that would prevent the string from being correctly located in the wellbore. Casing string design casing setting depths drilling. Participants should have a personal calculator and access to a computer with a spreadsheet software program. On the other hand, an incorrect casing setting depth decision can result in serious consequences. The results of the program will allow the well to be drilled safely without the necessity of building a steel monument of casing strings. Casing setting depth and design of production well in. Production casing collapse loads assumes zero pressure on the inside of the pipe and a final mud weight gradient on the outside of the casing. This shows there to be a cutoff percentage somewhere 5 and 10% ovality when planning a whipstock setting depth.
Conductor and surface casing depth requirements for deep. Wael summarizing how to solve casing setting problems. It provides comprehensive triaxial and workingstress design for burst, collapse, and axial installation, and servicelife loads to maximize the use of the most costeffective casing. All casing strings that utilized the ssr plug system and the plug locator collar successfully displaced the entire casing. Variform centralizer sub enables liner setting in highly.
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