PEH: Drilling Fluids - All drilling challenges relate to the fundamental objective of maintaining a workable wellbore throughout the well- construction process. A workable wellbore can be drilled, logged, cased, cemented, and completed with minimal nonproductive time. The design of the drilling- fluid system is central to achieving this objective. Most operational problems are interrelated, making them more difficult to resolve. For example, loss of circulation into a depleted zone causes a drop in hydrostatic pressure in the wellbore. When the hydrostatic pressure falls too low to hold back formation fluids, the loss incident can be compounded by an influx of gas or water, known as a flow or (when more severe) a kick. In these circumstances, the operator should increase the fluid density to stop the kick, yet avoid exacerbating the lost- circulation problem. Furthermore, the pressure differential created at the loss zone can cause the drillstring to become embedded in the wall cake, a situation called differential sticking. The drillstring should be freed quickly by mechanical or chemical methods because the longer it remains stuck, the lower the likelihood of freeing it. Failure to free the pipe can require an expensive fishing job that cannot be undertaken until the well is under control. Another example of interrelated problems occurs when the directional- drilling operation requires an interval of sliding, in which the drillstring is not rotated for a period of time but drilling continues by means of a downhole motor. Sliding allows better directional control, but the lack of pipe rotation can impair hole cleaning. Good hole cleaning is important in all wells, but it is critical in high- angle wells, in which cuttings might fall to the low side of the wellbore and form deep cuttings beds. Failure to remove the cuttings can lead to packing off of the drillstring. If the drillstring is severely packed off, attempts to circulate drilling fluid might lead to excessive pressure on the wellbore, which in turn can cause the formation below the packoff to break down. Incidents like these are not uncommon. The drilling fluid alone cannot correct all problems, but skillful management of the drilling- fluid system by a specialist can prevent conditions that lead to wellbore instability, thereby helping the operator to achieve a workable wellbore. Lost circulation always causes nonproductive time that includes the cost of rig time and all the services that support the drilling operation. Losing mud into the oil or gas reservoir can drastically reduce or even eliminate the operator. Prevention is critical, but because lost circulation is such a common occurrence, effective methods of remediation are also a high priority. Rock mechanics and hydraulic- fracture theory indicate that it is easier to prevent fracture propagation than it is to plug the fracture later to prevent fluid from re- entering. Other conditions that are prone to loss of circulation include natural and induced fractures, formations with high permeability and/or high porosity, and vugular formations (e. Using an LCM that can be carried in the drilling fluid without significantly affecting its rheology or fluid- loss characteristics facilitates the preventive pretreatment. Pretreatment can mitigate wellbore breathing (ballooning), seepage losses, and/or potential lost circulation when drilling depleted zones. Drilling consultant Suite 64 Bit. A discounted suite of programs. Special discount for Drilling consultant Suite 64 Bit. Get the latest upgrades at a discount (Click the image to view discounts) Five program suite. 5:53 pm Novo Nordisk A/S receives Complete Response Letter from the FDA regarding the New Drug Application for faster-acting insulin aspart (NVO): In the letter, the FDA requests additional information related to. See a rich collection of stock images, vectors, or photos for, hydraulic, you can buy on Shutterstock. Explore quality images, photos, art & more. Learn More Download our brochure for additional information about Hannon Hydraulics. SES (3D directional drilling software with Technical Hole Deviation) and FDS (rig-site daily drilling report software) features and links to FREE trial downloads. Field Tests The drilling-fluids specialist in the field conducts a number of tests to determine the properties of the drilling-fluid system and evaluate treatment needs. Although drilling-fluid companies might use some tests. Applied drilling engineering 1. Applied Drilling Engineering Adam T. Professor of Petroleum Engineering, Louisiana State U. Millheim Manager-Critical Drilling Facility. Sargent's Drilling Utilities is a drilling software program that performs most of the well-related calculations that the Man on the Rig needs in his day-to-day work. If you are a Drilling Supervisor or a Well Site Drilling. A properly designed and maintained drilling fluid performs essential functions during well construction such as transporting cuttings to the surface, preventing well-control issues and wellbore stability, minimizing formation. When a loss zone is encountered, the top priority is keeping the hole full so that the hydrostatic pressure does not fall below formation pressure and allow a kick to occur. The hydrostatic pressure may be purposely reduced to stop the loss, as long as sufficient density is maintained to prevent well- control problems. Loss zones also pose a high risk of differential sticking. Rotating and reciprocating the drillstring helps reduce this risk while an LCM treatment is prepared. If the location of the loss zone is known, it might be advisable to pull the drillstring to above the affected area. A variety of LCM is available, and combining several types and particle sizes for treatment purposes is common practice. Because lost circulation always has been one of the most costly issues facing the industry, a focus on healing the loss zone quickly and safely encouraged the development of proprietary materials that conform to the fracture to seal off pores, regardless of changes in annular pressure. In some cases, such deformable, expanding LCM is pumped ahead of cement jobs in which losses are expected. This type of material has a comparatively high success rate for the prevention and remediation of severe losses. Severe lost- circulation problems that do not respond to conventional treatments might be curable by spotting a hydratable LCM pill and holding it under gentle squeeze pressure for a predetermined period. At downhole temperatures, the LCM pill expands rapidly to fill and bridge fractures, allowing drilling and cementing operations to resume quickly, sometimes in 4 hours or less. Alternatively, rapid- set LCM products are available that react quickly with the drilling fluid after being spotted across the loss zone and form a dense, flexible plug that fills the fracture and adheres to the wellbore. In some cases, this type of plug has proved so effective that the natural fracture gradient of the formation actually increased, allowing the operator to resume drilling and increase the mud weight beyond constraints established before the treatment. The LOT is performed by closing in the well and pressuring up in the open hole immediately below the last string of casing before drilling ahead in the next interval. On the basis of the point at which the pressure drops off, the test indicates the strength of the wellbore at the casing seat, typically considered one of the weakest points in any interval. However, extending an LOT to the fracture- extension stage can seriously lower the maximum mud weight that may be used to safely drill the interval without lost circulation. Consequently, stopping the test as early as possible after the pressure plot starts to break over is preferred. Formation Integrity Test (FIT)To avoid breaking down the formation, many operators perform an FIT at the casing seat to determine whether the wellbore will tolerate the maximum mud weight anticipated while drilling the interval. If the casing seat holds pressure that is equivalent to the prescribed mud density, the test is considered successful and drilling resumes. When an operator chooses to perform an LOT or an FIT, if the test fails, some remediation effort. The internal cake pressure decreases at the point where the drillpipe contacts the filter cake, causing the pipe to be held against the wall by differential pressure. In high- angle and horizontal wells, gravitational force contributes to extended contact between the drillstring and the formation. Properly managing the lubricity of the drilling fluid and the quality of the filter cake across the permeable formation can help reduce occurrences of stuck pipe. Fig. Preventing stuck pipe can require close monitoring of early warning signs, such as increases in torque and drag, indications of excessive cuttings loading, encountering tight spots while tripping, and experiencing loss of circulation while drilling. Depending on what the suspected cause of sticking is, it might be necessary to increase the drilling- fluid density (to stabilize a swelling shale) or to decrease it (to protect the depleted zone and avoid differential sticking). OBFs and SBFs offer the maximum lubricity; inhibitive WBFs can be treated with a lubricant (typically 1 to 5% by volume) and formulated to produce a thin, impermeable filter cake that offers increased protection against sticking. High- performance- polymer WBFs that are designed specifically to serve as alternates to OBFs and SBFs exhibit a high degree of natural lubricity and might not require the addition of a lubricant. Lubricants for WBFs. The quality of the emulsion is important to a lubricant. If the lubricant is too tightly emulsified, it no longer functions as a lubricant. If the emulsion is too loose, there is a risk that the lubricant will destabilize into a stringy, semisolid material. Overtreatment with lubricants might cause flocculation of the drilling fluid because of oil- wet solids. Film strength is the main indicator of lubricant performance; generally, the higher the strength, the better the lubricant performance. However, environmental issues might arise with the use of certain high- film- strength lubricants. For this reason, alcohol/glycol- type lubricants, considered to be more environmentally friendly, have gained popularity. The alcohol/glycol lubricants also might perform better at low temperatures. The typical operating range for alcohol/glycol lubricants is 4. Sulfurized oils (e. High- film- strength lubricants generally demonstrate increased thermal stability. Other lubricant types include glass, plastic, and ceramic beads. Spotting Fluids. Spotting fluids that are used to free stuck pipe are formulated to first crack the filter cake and then provide sufficient lubricity to allow the pipe to be worked free. Time is the key factor in successfully freeing stuck pipe. Spotting fluids routinely are included in rigsite inventory so that the spotting fluid can be applied as soon as possible after the pipe sticks, ideally within 6 hours. The length of free pipe may be estimated on the basis of drillstring stretch measurements, allowing the operator to determine the stuck point and deliver the spotting fluid as accurately as possible. If circulation is possible, decreasing the drilling- fluid density might relieve differential sticking; however, stuck pipe might be caused by a well kick combined with loss of circulation in a higher zone, which would eliminate the option of an intentional reduction in mud weight. What do you do then..? Call the Mud Loggers..? Most of the code is written in VBA (Visual. Basic for Applications). West- Texas..! So, if you have any comments, any bugs. I have. received several emails from users around the world asking if I could make an SI. Metric) version. But not until I start coding everything in pure. Visual Basic. Net, and totally eliminate Microsoft Excel as the . Here you define. your drill string, the casing scheme, the hole size, hole depth and pump. Pump Pressure and. This page also has graphical presentation of a) the System. Pressure Loss down thru the drill string and up thru the annulus, b) fluid. The page also has a feature to graphically present the well. The BHA components are. Hydraulics Page All formulas are taken from MI's Drilling Fluids Manual. Balanced Cement Plug User Interface allows entering surveys, selecting various. The current . Not bug tested, and not fully developed. However, presently, it will calculate - based on the Preston Moore. Correlation - Slip velocity, ROP, porosity, etc. Pre- Recorded Well Date page Vertical Kill Sheet Program will produce the .
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