Although drilling is more expensive now and requires greater depths, operators and contractors everywhere are being compelled to learn about the advantages, strategies, and tools available to efficiently manage solids in a drilling fluid. Concentration levels of solids may be properly managed by using centrifuges, mud cleaners, desilters, and shale shakers. This talk will focus on the “whys” and “hows” of managing drill solids with this technology rather than the negative impact of drill solids on the formations themselves.
Different pieces of equipment, collectively known as “particle control equipment,” may be used to take solids from the mud in various ways.
As the mud goes over the shale shaker, it vibrates, enabling the liquid and tiny particles to flow through the screen. This filters the used drilling fluid, removing up to 80% of the particulates.
The drilling fluid may rest in the settling tank, which enables the bigger particles to sink to the bottom.
To keep the mud’s density constant, the vacuum degasser extracts the gas that has been trapped in the mud.
Desanders or desilters are two uses for hydro cyclones. They transform the centrifugal force of a centrifugal compressor into pressure, enabling the drilling mud’s suspended particulates to segregate from the fluid.
Barite is recovered for reuse using mud cleaners. They consist of a desilter positioned atop a fine-screened shale shaker and a high-energy oscillating screen.
Decanter centrifuges use centrifugal force to separate the liquid’s lighter constituents from its heavier particulates. A double-screw type conveyor that spins in the same direction also as a conical container but at a slightly slower speed makes up the conical container.
Equipment used to clear away impurities and trapped gas from spent drilling mud is known as solids control equipment in the setting of drilling fluid. The procedure uses apparatus like:
The carbon footprint related to the transportation and management of spent drilling mud is reduced because of solid management. It also significantly lowers project costs by enabling the cleaning and recycling of wasted drilling fluid for additional drilling.
Drilled cuttings are carried to the surface by the circulating mud during drilling operations. In the solid modeling control system, these materials are subsequently processed by being separated from the mud based on particle size. Since the previous design was ineffective at separating the solid from the mud, the study in this chapter focuses on improving the efficiency of equipment and isolation. In order to lessen pressure loss from movement, the high-pressure pipe was replaced with a flow line splitter at the end of the crossover passage to the shale shakers. With the help of this technology, the desired number of shale shakers may each get an equal share of the drilling mud-containing particles. Mud circulation that doesn’t result in a drop in solid concentration might increase the fluid’s viscosity and give the mud a resistance-to-flow quality. This results in modifications to its density, rheology, and other characteristics. To minimize downtime caused by clogged flow lines, fluid end repairs, drilling process erosion, and re-drilling of particles when drilling fluid recycles itself throughout the mud system loop, it is essential to remove as many solids as is reasonably possible.
There are several components of the system that may be divided into a few phases when it relates to solids control:
All of the big cuts that are present in the mud are manually removed by the shale shaker. They become silt since it does not remove any further tiny solid particles. You must take them out as part of the appropriate drilling technique. If you don’t, the weight can be heavier than it has to be. This is bad because it makes the circulating machinery heavier. Gas builds up as a result of this.
Gas that has gotten into the mud has to be taken out. A pump is a further tool needed for this. The mud will be circulated by the pump and returned to the pit. The shaker screens will subsequently be used by the shale shaker. Large clippings are caught by these and dropped into another receptacle for disposal.
The sand trap, which is more like a mud tank, receives the liquid mud. Although they seem straightforward, they are really quite intricate. They are intended to cause the screens to vibrate, which lowers the dirt content. A vacuum degassing will be used if there is too much muck.
The degasser brings the gas out of the mud once again. If it is left in place, the mud can be too light. If this happens, they just might fail, and a blowout may result if formation fluids are allowed to reach the wellbore. Furthermore, the gas may result in a gas lock if, indeed, the driller circulates this in cut mud.
It is possible to utilize pump gas with mud rather than simply mud, which is very inefficient. You may use a degasser to accomplish this. This is carried out in a vacuum-type device that also includes gas and dirt. It will flow out over the baffle plates after entering the top. The spreader will then provide a significant contact area for the gas to ignite. When the mud is distributed, the vacuum makes it incredibly simple for the gas to escape. For the sake of protecting the mud and environment, the gas will then exit the rig via a vent.
The bulk of drilling muds being used today is categorized as water-based muds since they utilize water as the water form. The remaining drilling muds used today are categorized as oil-based muds because they include oil as the permanent liquid phase. Drilling mud’s solid stages may be divided into two categories:
Drill solids are those solids that come from the formations being drilled and are introduced to the mud as cuttings or cavings. The particle sizes of drill solids range from less than one millimeter to 1500 microns and beyond. The duration that drill solids spend in the mud should be kept to a minimum so that they may circulate from the bit back toward the surface. Drill solids must necessarily be present in the mud. Naturally, the content of drill solids matches that of the structure being drilled or that has already been drilled in the well. Controlling the concentration, size, and type of particles in the drilling fluids is one of the key goals while drilling and well. By achieving this goal, several associated issues may be resolved over the life of a well. This issue persists throughout the well. It is the duty of good engineers, operations staff, drilling subcontractors, and mud companies to do this work. To achieve this goal, all of the aforementioned people must cooperate and comprehend.
The real cost of today’s modern drilling fluids is often a considerable component of a well’s direct costs. There are typically 1000–2000 barrels in a mud system.
Commercial solids are all those solids that are bought from the mud firm and mixed with the mud to give them the needed qualities for certain tasks. All commercial products carry out necessary duties. In addition to barite and LCM, all commercial solids contain particles that are less than just a micron in size (lost circulation material). According to Figure 1, the size distribution of barite particles ranges from 1 to 74 microns. Although the amount of lost circulation materials varies, barite is much smaller than LCM.
Numerous centrifugal pumps are often included in the mud system. A centrifugal pump may move a lot of mud while having a modest pressure output. Therefore, they are used in a variety of ways by crew members. One task a centrifugal pump often does is to supercharge the primary mud pump’s mud input. The little pump constantly maintains the larger pump’s suction line filled with mud by drawing it via a tube attached to it from a suction container. In the absence of a charge pump, the system relies only on gravity to supply the suction stream of the pump. Gravity sometimes fails to keep the mud input of the pump entirely filled. Gravity is unable to maintain the suction line’s fullness of mud because the pump pistons suck in the mud so quickly. A centrifugal pump is also used by the team to combine various mud ingredients.
A hopper (for mixing mud) is comparable to a large funnel. Crewmen filled it with mud in bags. However, they don’t combine caustic soda in the hopper. Dry caustic might be blown back through into the face of the person mixing the mud by the header (mud mixing hopper). Putting caustic via the hopper may flocculate the mud, which causes it to clump together, in addition to being harmful. An employee of the team opens the material bag at the bottom of the hopper and pours the contents into the funnels. A nozzle just at the bottom of the funnel receives a jet of mud from a water compressor at the same time.