Posted at 11.14.2018
A the greater part of operators want onward at monobore conclusion techniques as potential solutions to economic and operational challenges. This system can boost the conclusion process and the benefits associated with this idea influencing different stages of the well technology that can result in to a wide range of operational advantages. However, this philosophy requires employing purpose built equipments to be able to avail its advantages. The oil and gas industry is paying attention at functional efficiency and cost chopping methods and therefore, the professionals of the industry are in search of the techniques which have the potential to boost in these areas.
Monobore completion techniques have a tendency to provide a great degree of versatility for maintenance procedures that the operators are doting to accomplish. As per its design, the tubing does not seem to be to impose any limitation over any equipment that is found in the liner. This system reduces service costs since special tools are discarded for such wells. But these operational savings are not often known until very later in the development of the well since the cost benefits via monobore principle are incredibly much anticipated rather than instant which makes it hard to calculate the complete amount of additional cost for the conclusion process that is essential for making decisions about the intricacy of the down hole components. The restriction of monobore technology is the fact the traditional seal bores bring in may influence the actual performance of other down opening services which include those demanded by creation logging. The traditional design concepts can't be used to create the standards for monobore completions. For example, because of the reduced diametrical clearance, monobore completions will not comply with the normal designs of sub surface circulation control devices. In addition, traditional lock mandrel systems be based upon interference engaging packing so the plugs and the chokes can be covered.
This research paper will compare monobore drilling technology with its conventional counterpart based on the case studies of some specific olive oil fields. Also, it will discuss the monobore technology at length by specifying its costs and benefits. Furthermore, the paper describes the different the different parts of monobore drilling and also, studies different technical aspects of monobore technology.
TABLE OF CONTENTS
1. INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mistake: Reference source not found
3. 1 Disposal Monobore Completions 8
3. 2 Concrete thru Conclusion System 9
3. 3 Monobore Shot wells 9
Figure 1 demonstrating the typical conclusion used and projected for every of the conclusion types. 10
3. 4 Performance of Monobore Systems 10
The conventional completion is proven but therefore most expensive than its other counterparts due to the inclusion of zonal isolation, cased well bore, basic safety valve and standard gas lift side pocket mandrels. The monobore completion shown in the number above is the throw-away well completion that includes safety valve, tubes and cemented in place. It is most cost effective completion because of its simplicity. However, it generally does not offer unloading the well and the creation increase for the well. Furthermore, it does not allow remedial work to install any rig so the life of a well can be increased because the packed is not included in this design. 10
Figure 2 exhibiting the design process with the comprehensive fluid powerful simulations to demonstrate the substance characteristics through the conclusion process. 11
It was necessary to identify the areas where the residual cement was left behind after the cement was pumped out. SPM was found to be the most significant area which can make it hard to displace the gas lift valve or the dummy valve. The areas highlighted in the number 2 are those where in fact the design improvements were reassured to cause turbulence and let these critical components clean on their own? Security valves use the same design concepts to limit the assortment of sand in them and this illustrated the necessity of turbulent circulation over the SPM body. 11
Monobore completion techniques are attaining more attention in the modern world of well drilling. 'Monobore' refers to the conclusion that employs regular size of the conclusion string ID through the well. The advantages of such completions are classified in to two basic categories: well development and remedial businesses anticipated to which monobore completions are given preference over standard completions. However, it includes certain limitations too. Monobore wells are fundamentally pursued credited to reduced drilling cost and range of specialized machines as these directly influence the expense of completion. Most of the wells would have been impractical if indeed they need to be completed through the traditional approach. However, such unfeasible wells would become better marginally, or profitable or even highly profitable occasionally if they used a system through which both the rig time and the gear list, such as packers, sliding sleeves, etc. , could be reduced while managing to securely complete the well. The earliest methods included cementing the completion in the wellbore. Later methods include staging the concrete process so that the instruments increasing the well's life and ascertaining its safe procedure could be included.
This newspaper discusses several methods regarding monobore well design that will save significant time through minimizing the complete cost of conclusion. A significant number of studies have been recently executed in order to establish a system that is more lasting to complete these wells and increase their efficiency which makes them even more appealing to the operators. Detailed methods will be discusses with the aid of the illustrations that talks about the various talents and limitations of each conclusion method in a well completion process. Each method will be supported through circumstance studies.
The analysis is targeted towards looking into and evaluating the appraisal methods of current and future techniques of monobore wells.
In order to achieve the above mentioned target, the following aims should be performed in this review.
Describe and clarify the monobore wells along with their costs and benefits compared to the conventional drilling techniques.
Study the idea of monobore wells and the different methods of monobore completions.
Conduct feasibility of the well to package by comparing the traditional and mono-bore drilling with each other.
Apprehend the future development of mono-bore wells, and recommend research and development work that may cause the current applications to increase.
Contemporary well could be classified as brief life or harvest wells out of which some are economically unfeasible since they employ top quality conclusion rigs and methods. This problem could be fixed through monobore wells. A well is grouped as a monobore completion if it has sole production tubing size right a way from pay zone through out the surface of completion. Even though there monobore completions have some limitations however they also have various benefits such as reduced drilling cost and lesser variety of rigs, which include packers, sliding sleeves, etc. , mixed up in drilling process in comparison to its other counterparts. A lot of wells which were infeasible through the traditional completion regimes have found to be carefully and efficiently finished with monobore completion system. That's the reason this completion technique has acquired the attention of many providers and researchers and thus, it is extensively applied to horizontal wells today.
Cementing the completion in the wellbore is regarded as one of the most primitive methods used. Then this technique was improved by staging the process by using equipments to make the well previous long along with functional safety. A lot of studies and studies have been completed so a more reliable and improved upon system of conclusion could be developed for concluding these wells with increased output. Tank and wellbore hydraulics simulations have been researched for a long period. Researchers are actually focusing on the interaction between your fluid moves of reservoir and wellbore because the horizontal wells are extensively applied. The benefits of utilizing monobore completions are now easily acquired since the industry is willing towards higher rate gas completions. These advantage of monobore completions are classified as: well creation benefits and remedial functions benefits.
Increased tubes size in monobore completions that also increases the deliverability of a well.
Lesser number of wellbores is performed to successfully drain the tank.
This can reduce the range of required programs, especially in case of the offshore jobs.
Reduction in the operational and maintenance cost because of the decrease in the amount of well bores.
Increased strength and reliability since the monobore completions are simpler in comparison to their traditional counterparts.
Further, the gas turbulence areas are reduced due to the elimination of interior restrictions.
Remedial functions benefits are actually known towards the end of the field's life.
The elimination of internal limitations also helps it be simple to run services and for intervention instruments.
Moreover in monobore completions, the liner top can be completely seen which permits easier mechanised isolation or squash.
The need of getting compression on line can be postponed due to the increased tubes size as it reduces the frictional pressure drop whilst creation.
Field development time is also reduced through jogging 95/8 in. monobore. This reduced time allows the operators to produce first gas previously or start the project as later as the time being kept. Thus, the net present value of a huge project is significantly afflicted. Usually, this increase in value is higher than the price of increasing the tubes size.
Monobore completions can deliver higher outcome than the expected production.
The Coal and oil industry has the prime concern to complete the well in the most efficient and affordable manner. A whole lot of researches, as mentioned previously in this newspaper, have been conducted in the periods of time to make the process of well completion as safest and successful as possible. Like any other technology, well completions likewise have several benefits and drawbacks which fluctuate with the various techniques used for well completions. Out of these various well completion techniques, monobore completions have found to provide better benefits as compared to their standard counterparts. The essential definition and different advantages of the monobore completion systems have been talked about in the previous section. So, this chapter will focus on the various ways of monobore completions because the application of the right method will be most beneficial for the well conclusion. The monobore completion system works as a single trip mechanism that permits the operator to drain out the cement when you are offline, so the platform can make use of the tools at its different locations. Different ways of monobore completions along with their costs and benefits are explained further.
This method is dependant on open or cased holes and it is also known as as upper hole completion. Since tubes is the only real conduit to the top therefore successful cementing is very essential in this technique. A lot of the times very limited variety of rigs which include packers, gas lift mandrels, slipping sleeves and surface controlled sub-surface safeness valves, are needed by these completion methods. The best objective of this method is to reduce the cost of the conclusion. Such wells are perforated across the pay zones that's the reason zonal concern is one of these problems.
This is a real monobore system that performs after the cement is drained out. It uses pressure cycles for the various rigs to operate. The method is targeted towards finding out the impact of the rest of the cement on the well bore integrity. Such systems raise the potential to eradicate additional trips that decreases the associated safe practices issues. This method also reduces rig time thoroughly. Brief life wells using this method significantly save cost and also improve safeness and output. Furthermore, this method minimizes the fishing operations that soon add up to cost and time. Staged cementing approach can be used in an software in which open gap cementing method could not possibly be employed.
This method reduces rig time of drinking water injection well conclusion. Subsidence creation is the basic problem in this method that usually damages the casing disabling the well. The method preserves tubular integrity and reduces the rig time almost by 4 times with reduced number of rigs used because of its ability to cement through the tubes.
Source: Ingvardsen et al. , 2009.
Source: Ingvardsen et al. , 2009.
Figure 3 showing the comparison between your conclusion time of the previously known disposable conclusion system and the latest concrete thru completion system.
Source: Ingvardsen et al. , 2009.
This newspaper will further summarize the development of a monobore well system emphasizing over the selection criteria for the materials, field studies and other system development periods. This section of the survey will particularly treat the different operational and deployment methods and stages for the development of the well system along with the chronicle testing program that includes field tests.
The system under consideration here characterizes a level methodology for the monobore well development program. This technique deploys an expandable liner through the casing portion of intermediate length. The liner is widened below this intermediate size casing section along with maintaining the same Identification as that of the intermediate string. A recess account stationed at the then end of the intermediated string is utilized to connect the system with the intermediate casing string. The technique of top down expansion is employed to change the casing to and from its 'run in' and 'post growth' says after being deployed to depth.
The first stage of the machine can be involved with executing a particular recess shoe at the end of the intermediate casing string instead of the typical casing cement sneaker. The protective ID of this recess shoe inhibits concrete from reaching the shoe ID which is bored to death easily by the standard bits. The expandable liner is deployed such that the traditional casing getting the caveat materials and connections have the ability to broaden along with retaining the pressure integrity. Silicone coated pipe areas providing the annular closing potential, can be found at the required tips in casing string. These plastic components stretch out as the tube expands contrary to the open opening wellbore. Future systems will use the cement as the annulus sealing medium.
The liner expands from top to down after the range has been arranged down hole with the help of the hydraulic mechanical system. A similar tool is used in this expansion system as the the one that was to take the liner to the depth. A taper shaped circular cone is utilized to extend the tube. This cone moves through the liner to boost the run in proportions of the liner to its post development size. The device of hydraulic piston and anchor mixture is employed for producing the energy required to move the cone through the pipe. This system starts functioning when the pressure put on the wellbore drill tube is converted directly into mechanical linear power by using the down opening piston that is linked with the extension cone. A hydraulic anchor experiences the force produced by the piston meaning the piston concurrently triggers the pressure. The anchor helps to protect the upper part of the piston through to the encompassing casing and hence, applies the response make that inhibits the drill pipe from moving upward with in the hole since the piston strokes the cone down the wellbore making tube expand along its stroke duration.
The body 4 provided below illustrates a proper onshore Egypt where "shales packed off surrounding the drill string before the 12 -in. open-hole section could be completed. The well had been designed to 4, 600 m and needed to have a 9 5/8-in. casing below 2, 950 m to accomplish exploration aims. The 9 5/8-in. casing halted at 2, 859 m. The monobore expandable liner was earned. The first look at failed, but the second attempt was successful. The 8 -in. open-hole section was drilled out of the extended liner to 3, 890 m" (Drilling Company Journal, 2010).
Figure 4: A proper onshore Egypt saved because of the Deployment of Monobore Expandable Liner Extension.
Source: Drilling Service provider Newspaper, 2010.
The software is the growth of the current and validated strategy of the Hydraulically Expandable Tubular System that can be used in other expandable products as well. The application form considered some components of Finite Element Analysis (FEA) modelling encouraging the machine design. The extension method is performed such that:
the liner is hung
fixed set up by using the cement
hanger is sealed
desired mechanical properties of the machine are achieved
This paper illustrates the feasibility research for a hydraulic expandable liner hanger. Studies have been conducted with the purpose of finding the possibility of utilizing the Hydraulically Expandable Tubular Technology (HETS) to be able to develop the slim well liner hanger system that minimizes the down-hole tools along with providing a life of well, weight bearing, steel to steel and pressure tight connectivity. Corresponding to its character, such a design will consider much smaller clearances between your current casing and the liner in contradiction to the traditional hangers.
This strategy provides numerous potential advantages such as:
Its futuristic design is congruent with the trim well viewpoint.
Reliable deployment because the removal of packers and elastomers simplifies the conventional liner hanger.
Better operating stability because of the simpler material to metal design seal.
The essential intermediate casing string contingency is obtained in the well construction process due to the lean design of the system.
Improved well design envelope such as under the sea applications.
4. 4 Developed Enlargement System-Validation of expandable monobore liner extension
Concept: A case study
Initially the purpose of an expandable monobore liner extension was to permit the operator to dig deeper explorations and development wells bearing the larger slots at the reservoir. While using contingency plan the target is then set to permit the operator to isolate areas having reactive shales, formations of low fracture gradient or other drilling constraints with out lowering the casing and size of the gap in the reservoir. The feasibility of the expandable monobore liner expansion principle was validated through the creation of the one-trip-top-down development system that optimizes the casing configuration along with reducing the price but devoid of reducing how big is the drilled hole.
The amount 5 given below shows the Kristin and Kvitebjёrn domains that will be the HPHT gas and condensate domains at the Norwegian sector of the North Sea. Kristin is situated in the southwestern part Halten Bank or investment company whereas the Kvitebjёrn is situated in east of Gullfaks. Kritin has the stresses at 1300 psi and temperature at 340oF. The expandable system formed is determined by these values. In addition, Kvitebjёrn needed some elastomers as the materials to avoid chemicals. Both Kristin and Kvitebjёrn are depletion drive but later their drilling and completion activities expected to happen in a moderate to high depletion tank.
Figure 5: Kristin and Kvitebjёrn fields
Source: Drilling Contractor, 2006.
These domains may face the challenge of drilling new wells when depletion has taken place significantly. The fracture gradient reduces along with the depleting zones. Differentially stuck pipe and fluid deficits can cause these fields because of the extreme pressure difference between the hydrostatic pressure of the smooth and the pore pressure. Even the pressure preserved areas may face depleted isolated packets resulting in drilling problems. Thus, these areas require the next four objectives to accomplish.
pressure and good control of open-holes
reduce non-productive time to aid well-bore
economics that require 7 inch production liner for the reservoir
The resulting challenges credited to (a) hole stability maintenance and (b) potential tank harm control in the introduction of the fields under consideration require to reject the determined drilling contingencies for improving economics of the fields.
The traditional contingency method would require working 7 inches liner along with 41/2 inch completion for solving the drilling problems. However, for sufficient development during depletion, the 41/2 in. completion seems to be always a significant limitation in spite of accepted in some fields.
Different solutions were considered for evaluation for reaching the project targets. Well and casing design proposed 7 inches production liner to be fixed at 13944 ft vertical depth altogether. The history of both the fields signifies that depth could be performed through achieving the forecasted change of possible pressure around 870-1450 psi anticipated to depletions. The range of the real change of pressure wouldn't normally be decided prior to drilling the shale portions below the estimated 95/8 in. intermediate shoe depth at 12992 ft total vertical depth. To keep such worth of pressures, wellbore steadiness and tank depth for the 7 inches production liner, the planners measured that a less than 435 psi change of pressure would fulfil the standard design and objectives. Alternatively, a change of pressure greater than 435 psi would compel the execution of the contingency drilling program. However, these procedures met all except one project target of economic goals because the production liner would be decreased to 4. 5 inches. Planners unveiled and analyzed the contingency monobore systems for both fields based on their affect on all the four job objectives.
A prototype trial was executed on the proposed expandable liner system. Initially the ultra-sonic (UT) inspection was performed in the 75/8 inch liner and then it was executed in the well where free-end expanded to 22%. Surface breaking fractures were noticed as the tube retrieves after extension. After this trial, the size of the tubulars modified from 75/8 in. to 8 inches in outer diameter which further, reduces the expansion percentage to 18% from 22% and also lowers the significant stresses in the pipes.
Another trial was executed on the system in some time following the first trial. Again all the joint parts were UT inspected before the trial. This inspection of the 36 bones of the casing inferred that pressure test was applied on the string and also, the full period magnetic particle inside (FLMPI) inspection was performed on it. It was found that the two joint parts have surface signs as can be seen in figures 6 and 7 given below.
Source: Drilling Builder, 2006.
These results identified the need for an enhanced pipe inspection. A better UT inspection was designed by using 18 shear transducers. These highly sensitive compression transducers measure even low level problems just underneath the exterior diameter surface.
Later another trial was carried out having 27 joints through the new inspection method to be able to select the tube that was considered not suitable. The broadened liner was inspected and retrieved through the wall structure. It was discovered that the string carry no defects with near-surface inclusions.
Several monobore systems were analyzed carrying out extensive prototype screening and system certification to satisfy the operator. The chosen contingency system further summarized a staged method of monobore well program.
The existing system in these fields deployed expandable liner with the aid of the current intermediate casing section and run to depth. This new liner is further, expanded below the intermediate section while maintaining the same internal diameter as that of the intermediate section. A recessed profile in the contingency sneaker connected the monobore system with the intermediate casing string.
Source: Drilling Company, 2006.
The contingency sneaker run associated with the intermediate liner works as the normal casing shoe, however, it also provides a recess area and location profile for the liner, if required. The main one trip monobore expandable liner can be used and deployed with the help of the very best down approaches for expansion when it is concluded that drilling program contingencies must be used to attain the well objectives. If the hydraulic reaches near the sneaker of the expandable liner then it is removed on a single trip through retrieval tool latches upon a retrievable guide shoe. The Kristin utilized the contingency recess sneaker on the intermediate liner for not cementing the expanded liner as shown in physique 8 above while the contingency recess footwear for the Kvitebjёrn field employed slipping sleeves and plug-ins, as shown in body 9 listed below, to allow for cementation and stream area of the liner.
Source: Drilling Contractor, 2006.
The improvements in coal and oil drilling is not simply limited to creating the gap through the most advanced technology and techniques, these are rather concerned with safeness, risk management, strategy, eco-protection, experience, trustworthiness and economics, in particular and most importantly. The main element benefits that the operators be prepared to achieve from drilling activities and system are mentioned below:
Reduce non-productive time
Reduce output time by making the output process fast.
Increase overall productivity of the well.
It has been discovered that operators like to continue with the prevailing technologies until the new systems are which can provide better results for cost and risk attached with the deployment.
Hole enhancement is highly important to the success of the operating expandable tubular and screens. The conclusion of the work is exquisitely predicated on the quality of the prepared borehole enlargement required.
Since the prior 8 years, there have been significant initiatives applied in the introduction of hole enlargement tools in order to improve its output and reduce its cost/bills. This growing use of expandable tubulars and mono-diameter technology, in particular has presented new difficulties that current tools are incompatible and thus, recommended the necessity for new Gap Enhancement (HE) technology and products.
Currently, expandable tubulars are providing the basis for the further development into the future technology so that the remaining obstacles to advancements in deepwater and ultra-deep normal water can be destroyed. The brand new technology is situated upon monobore well. Some experts propose that a proper comprising of an individual casing diameter from the very best tree to the bottom would thoroughly save steel due to fewer cuttings. The future technology may possibly combine the expandable tubular technology with the managed pressure drilling integrated with casing and liner drilling. Both most significant drilling challenges to come seem to be:
accessing reference, and
availability of technological expertise
This is principally because of that the oil and gas industry is switching from vertical to deviated- horizontal drilling solutions at a considerably faster tempo. Drilling systems are reliant on drivers for his or her execution. The important drivers include safeness, risk, business strategy, environment coverage, and above all engine oil field economics and operator necessities.
The well development technology emphasized over the next two basic areas in the entire year 2009 (SPE 121548).
Well construction assignments regarding deepwater completions and high pressure-high -heat range established completions.
Studies and researches on the consistency of carbon get and sequestration storage area (CCS) wells have been carried out.
Beyond the opportunity of theses principal areas, studies on engineering practices related to with shale takes on also came frontward in the previous year. The largest challenge in enabling the deepwater wells to attain the concentrate on depth is the lost blood flow which is yet to triumph over. The development and depletion in these areas have led to the aggravation of this problem of lost blood circulation because of the drop in the pore pressure. Development in CCS generally depends upon the prolonged isolation of the induced CO2. It isn't yet known for certain for the CCS well engineering that the long-term integrity of such wells relies on which of both: non-Portland or lean-Portland cements are being used (SPE 121548).
It has been found that the tubing sized monobore completions can develop effective and successful complex multi-layer reservoirs. The elaborate part of such completions is the simplicity and consistency of the line collection components that are needed in these small monobores.
In order to boost hydro-carbon production and prevent undesirable fluid entrance, the targeted tiers are opened up and sealed in the life span of the field. Such circumstances often require nipple-less retrievable bridge plugs so that the specific reservoir can be isolated. The prevailing tools in this regard are not ready enough to provide the purpose because of their conventional rubber sealing element. So, a fresh tool has been designed to beat these issues. This tool works with a segment sealing wedding ring that enlarges when the blocks are mechanically displaced.
Hydro-carbon production is optimized through creating affordable small pay zones in the past 2 decades by making use of the cemented liners or the perforated tubing. As a development step, the conclusion architecture has eradicated the traditional getting nipple due to the production layers increasing to 70 in number. This development is further backed by the demand for the exquisitely reliable liner cementations that carry the perfect wiper plug efficiency. Furthermore, this system permits the operator to efficiently and effectively exploit the multi-zone wells, which likewise incorporate high temperature reservoir, since it inhibits the cable tracking brought on by the landing nipple seal bores and the conclusion packer based on the rubber seals.
The tests on the traditional completion packers have produced unusual results. Operators are incredibly well alert to the fact that all the real reason for the inability of the existing lock mandrels is their plastic sealing ring factor. This rubber-seal-ring swells due to the influence of heat range and gas and pieces sometimes only. The plastic seal must be extremely stressed so the wall space of the bore-hole and the engagement ring of the lock mandrel are properly air tight and also it must possess a low expansion ratio in order to safeguard the gasket. The rubber seal also losses its condition forever once it is swelled and solidified anticipated to which it can't be retrieved easily.
Therefore, the elements in the down-hole, condition the irreversible deformation of the rubber seal ring and therefore, retrieve of the prevailing designs. The axial displacement between your anchoring slips and the sealing ring also facilitates lock mandrel to keep its setting.
Various initiatives have been put on beat these issues but none of them of then have contributed to the successful resolution of the determined problems in one go. A simple multi-purpose tool is therefore, very much awaited in order to meet the numerous requirements of creation, drilling, and well servicing and maintenance.
The conventional plastic pack-off wedding ring is divided into a assortment of matched tapered blocks based on the validated concept of unidirectional blow-out preventer seal ram memory that can undo all these restrictions of the closing element. Exactly the same amount of top and bottom sealing elements assemble together basically in trapezoidal form, alternately in two rows to create the segmented diamond ring. The blocks are allowed to displace with regards to each other and in between the usual contracted radial agreement, which is present inside the radial size of the lock mandrel holder, and the extended radial arrangement where the one part surface of the stop pushes the medial side surface of the neighbouring block.
The closing parts are contained inside a steel structure where the continuous lip area surround sealing element. The mouth protect sealing aspect as they provide as the obstacles to extrusion. The traditional extrusion gaps are removed by shaping the clear plastic strains up against the tubing, lock manderal and inserts since the sealing part steps together with the metal insert.
The blocks are compressed from three sizes by congruent circumferential and radial wedging results to be able to provide closing between trapezoidal blocks and the entire block collection and also between the tapered stop bearing surface of the ring and the tubing wall.
The materials getting the low amount of deformity such as vinyl or metal are used on comparison to the rubber materials that is vulnerable to deformation. Thus, the blocks do not come in contact with the down-hole liquids and aren't influenced by the explosive decompression. The kinematic seal theory is capable of undertaking up to the temps of 500o F and the differential pressure of above 10, 000 psi devoid of the extrusion difference and even for long durations under any chemical environment.
The reversibility of the expandable seal is increased by using the Polytetrafluoroethylene materials as the closing element since it generally does not allow the blocks to are exposed to the tubes, lock manderal and the neighbouring blocks even under prolonged down-hole publicity. The complex expandable seal is related to the reliable and foolproof development in the mandrel system, of extending monobore completion, having intrinsic pre-stressed return springs. If the manderal lock works in the opening, these springs keep carefully the seal and the anchoring slips in their original or usual contracted radial settings and form. During the configuration of the set up, the return springtime are compressed such that they store satisfactory energy required to enable the mandrel to come back to its prior contracted configuration.
The compressed go back springs also provide the goal of maintaining a perfect sequential layout with out giving any shear pins in the gap. First, the manderal centralizes the whole string tool through the congruent development of the anchoring slips and the sealing components of the first row after which the next row of the blocks is also widened that permits the anchoring slips to lock the manderal at its position prior to sealing.
The reacting torque, necessary to place long strings under any inclination at the installation point, is increased due to the large distance among the seal portion and the anchoring slips. This distance will not vary during construction and thus, increases the retrievability of the system. A ratchet mechanism that runs only after anchoring defends the whole manderal. Thus, manderal is held completely reversible and can be drawn out of the opening until the slips indent in the tubing wall membrane. Due to this feature, the agreement of the lock is stopped to come back to the initial running construction till it is anchored. In this process, both the rows of the blocks are involved in to each other only following the lock is anchored anticipated to which a circulation area is left in the mandrel environment prior to sealing. Thus, the design of the tool reduces the undesirable cross flow results during configuration and retrieval and secures the closing elements from rubbing on to the tubing wall membrane.
The technology brings both short radial design and the high development proportion. Calibrated shear disk is used as opposed to the traditional shear pins so that a flush flow tube is left following the setup with out leaving any material parts such as the studs or shear pins in the well. Therefore, this new tool facilitates the flowing application which include basic safety valve, check valve, shut in tool, and straddle packer set up open tubes of small size of 27/8 inch. The technology is generally applicable even under restrictions such as landing nipples or in horizontal areas, for closing a lock manderal and also for:
Testing the tubing for leakages at different areas but at the same run.
Complete circumferential range scrapping utilizing the pineapple segments instead of the seal blocks. This procedure is excuted prior to preparing the lock to ascertain the environment performance.
Taking the impressions of the tubing wall membrane, locally utilizing the metal instead of the silicone or clear plastic part.
The ratchet of the manderal is removed for these applications and fool substantiation stroker is compulsorily required to permit multiple expansion-retraction cycles in the same run. A GR-type tugging tool is utilized along with the light slickline device to be able to get the lock manderal in an inexpensive manner.
Various field trials of this technology were carried out which concluded that the monobore completions present the most likely well structures that decreases the bills and maximizes the restoration rate through perforating and then turning pay areas sequentially from ruthless layer to the low ones (SPE 121548).