Kick pressure

Stress changes at the transition, causes a kick pressure ... 

When any core flow channel spreads to meet the walls of the container below the surface level of the stored material, the upper region of the flow channel is of bed flow type. This combination is termed mixed flow . This is an important form to recognize, because a kick pressure will be created at the transition where bed flow changes to a converging core flow... 

An important safety feature on every modern rig is the blowout preventer (BOP). As discussed earlier on, one of the purposes of the drilling mud is to provide a hydrostatic head of fluid to counterbalance the pore pressure of fluids in permeable formations. However, for a variety of reasons (see section 3.6 Drilling Problems ) the well may kick , i.e. formation fluids may enter the wellbore, upsetting the balance of the system, pushing mud out of the hole, and exposing the upper part of the hole and equipment to the higher pressures of the deep subsurface. If left uncontrolled, this can lead to a blowout, a situation where formation fluids flow to the surface in an uncontrolled manner. 

Surface Equipment 1101. When and How to Close the Well 1101. Gas-Cut Mud 1103. The Closed Well 1105. Kick Control Procedures 1106. Maximum Casing/Borehole Pressure 1111. 

One area where MWD would be most useful is drilling safety and, particularly, early gas kick detection and monitoring. Conventional kick monitoring is based on pit gain measurements and all other available surface indication such as drilling rate break, injection pressure variation, etc. 

Abnormal Formation Pressure Detection from Kicks. The kicks, or flow of formation fluids into the borehole, are the ultimate indication that the well has encountered an overpressured zone. Kick detection during drilling usually is achieved by use of a pit-volume indicator and/or a flow indicator. The usual pit-volume alert is 10 barrels drilling fluid volume increase. A differential mud flow indicator can also be used to detect kicks more quickly. 

These techniques will work for gas, oil, or water inflow with any types of mud, water-base or oil-base. For gas inflow in oil-base mud, large amounts of gas go into solution at high pressures and reduce the flowrate increase. The change is less important, if detectable, with oil or water entry. The gas in solution in oil-base mud cannot be detected easily. The latest and most promising equipment is the kick alert (Anadrill). Figure 4-343 shows a schematic of Kick Alert."... 

Basically all formations penetrated during drilling are porous and permeable to some degree. Fluids contained in pore spaces are under pressure that is overbalanced by the drilling fluid pressure in the well bore. The bore-hole pressure is equal to the hydrostatic pressure plus the friction pressure loss in the annulus. If for some reason the borehole pressure falls below the formation fluid pressure, the formation fluids can enter the well. Such an event is known as a kick. This name is associated with a rather sudden flowrate increase observed at the surface. 

A formation fluid kick can be efficiently and safely controlled if the proper equipment is installed at the surface. One of several possible arrangements of pressure control equipment is shown in Figure 4-351. The blowout preventer (BOP) consists of a spherical preventer (Hydril), blind and pipe rams, and the drilling spool. 

If the kick is gained while tripping, the only warning signal we have is an increase in fluid volume at the surface (pit gain). Once it is determined that the pressure overbalance is lost, the well must be closed as quickly as possible. The sequence of operations involved in closing the well is as follows ... 

Since the hydrostatic pressure of the original mud is 5,214.7 psia, the reduction in the hydrostatic pressure is about 69 psi. Because the pore pressure at the vertical depth of 10,000 ft is 4,700 psi, the hydrostatic pressure of the gas-cut mud is sufficient to prevent any formation fluid kick into the hole. 

Upon shutting in the well, the pressure builds up both on the drillpipe and casing sides. The rate of pressure buildup and time required for stabilization depend upon formation fluid type, formation properties, initial differential pressure and drilling fluid properties. In Ref. [143] technique is provided for determining the shut-in pressures if the drillpipe pressure is recorded as a function of time. Here we assume that after a relatively short time the conditions are stabilized. At this time we record the shut-in drillpipe pressure (SIDPP) and the shut-in casing pressure (SICP). A small difference between their pressures indicates liquid kick (oil, saltwater) while a large difference is evidence of gas influx. This is true for the same kick size (pit gain). 

Assuming the formation fluid does not enter the drillpipe, we know that the SIDPP plus the hydrostatic head of the drilling fluid inside the pipe equals the pressure of the kick fluid (formation pressure). The formation pressure is also equal to the SICP plus the hydrostatic head of the original mud, plus the hydrostatic head of the kick fluid in the annulus. 

Figure 4>352b. Driller s method—Schematic diagram of casing pressure vs. time, t = kick fiuid out the top of the hole t = kick fluid out of the hole t = kill mud at the bottom of the hole t = killing procedure completed.

Phase 4. During this phase the original mud that follows the kick fluid is circulated out of the hole and a kill mud fills up the annulus. The choke is opened more and more to keep the drillpipe pressure constant. At the end of this phase the safe pressure overbalance is restored. 

This method can be used if the kick is taken during tripping up the hole with the bit far from the bottom of the hole. Again the constant bottomhole pressure principle is used to control the situation. 

The magnitude of the casing pressure during kick control is... 

Determination of the maximum expected casing pressure is required for selection of the kick control technique. If the driller s method is used for kick control, the maximum casing pressure (psi) is calculated assuming gas influx into the hole. This is... 

Calculate the maximum expected casing pressure for the driller s and engineer s techniques of kick control for the data as below ... 

Solving the above equation yields p, = 5,561 psi. Since the maximum expected pressure in an open hole is less than the formation fracture pressure, the kick can be safely circulated out of the hole. 

When the well is circulated through the choke line, a rapid loss in hydrostatic pressure is seen when the kick fluid begins to enter the choke line. Hydrostatic pressure is lost because low density gas is displacing the drilling mud from the small volume of choke line. Small kick volumes can result in long columns of gas in the choke line. Surface choke response must be rapid enough to prevent new kick fluid from entering the well due to the reduction in bottomhole... 

Muscle spasm, fever, nausea, vomiting, kicking movements, weakness, depression, body aches, weight loss, severe backache, abdominal and leg pains, hot and cold flashes, insomnia, repetitive sneezing, increased blood pressure, respiratory rate, and heart rate... 

Diverter - The part of the bell nipple at the top of a marine riser, that controls the flow of gas or other fluids that may enter the wellbore under pressure, before the BOP stack has be set in place. It is used when drilling through shallow underground gas zones for diverting gas kicks in deep high pressure zones. 

While the ongoing story about new product development has unfolded, the parallel, more technical side of the saga has continued—catalysis, the science that made it all possible. In the early processes through the 1940s, the commercial polymerization processes used free radical, peroxidcr base catalysts to kick off the polymerization reactiom.The popular catalysts included t-butyl peroxypivalate, r-amyl peroxypivalate,. t-butyl hydroperoxide, and t-buryl peroxybenzoate, chemicals you don t run across every day. These catalysts were typically used in high-pressure processes to produce branched LDPE. 

The effects of such collisionally induced kicks are treated within the so-called pressure broadening (sometimes called collisional broadening) model by modifying the free-rotation correlation function through the introduction of an exponential damping factor exp( -Itl/x) ... 

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