Workover Kill Fluid Density Calculation

Friends, here is the simple Workover Kill fluid Density calculation, hope would be helpful to all:

Kill Fluid Density : {(SBHP + 35 or 75) x 624.25   } / TVD , lbs/cft

where, SBHP = Static bottom Hole pressure , kg/cm2TVD = Total Vertical Depth = (Total Depth - Deviation Correction ) , m35 is the conversion factor for Oil Wells 75 is the conversion factor for Gas Wells

Link OK : http://www.wellcontrol.com.br/?pag=methods

Methods & Concepts

The Driller's Method - Others formulas - Example in Simulator -

Well Control Methods applied on the drilling of the oil wells

The Driller's Method

During drilling operation of oil wells, there may be inflow of formation fluids into the well, which is an undesirable

condition. The driller should detect such events and closing the well immediately. Record information after the closing

of the well corresponding to stabilization of pressure, volume gain, SIDPP (Shut-in Pressure Drillpipe) and SICP

(Shut-in Casing Pressure. In the case of operations on floating units, this term could be redefined as Shut-in Choke

Pressure).

The control method to be applied is the driller's method. That is to circulate the influx even with the original weight of

the mud, keeping constant the circulation pressure named ICP - Initial Pressure Circulation. The second circulation

should be made with the kill mud weight in two steps: 1. Fill the drill string until the bit by keeping the pressure on the

kill line constant and equal to SIDPP. 2. Complete circulation of the annulus to the surface keeping the pressure of

circulation with the kill mud constant named FCP - Final Pressure Circulation.

Attention: about drill bit off bottom

This method should only be applied with the drill bit in the bottom hole or when the kick is completely in annullus of

the column. To minimize errors of calculation of the kill mud weight, the calculations made in this application

considers the depth of the drill bit instead of the depth of the well to calculate the kill mud weight. The formation

pressure consider the depth of well. In case of top of the kick bellow the bit, it is recommended to apply the volumetric

method until kick go through the drill bit to the annular, following then the driller's method.

Formulas:

ICP = Pks + SIDPP

ICP - Inital Circulation Pressure, psi Pks - Recorded pump pressure at the kill rate speed, psi SIDPP - Shut-in Drillpipe Pressure, psi Notes about floating units: a) Pks must be recorded by circulating riser; b) Record the friction loss in the choke line at the kill rate speed, psi;

KM = OM + SIDPP / (0.052 x TVD)

KM - Kill Mud Weight, ppg OM - Original Mud Weight, ppg TVD - True Vertical Depth, ft

FCP = Pks x KM / OM

FCP - Final Circulation Pressure, psi

Summary of method

STEPS PUMP PRESSURE KILL PRESSURE CHOKE PRESSURE VOLUME TO PUMP

Bring the pump to kill speed - SICP SICP - Choke line friction loss -

Circulate out the influx to surface ICP - - Annulus Volume

Circulate to fill drill string with kill mud - SIDPP SIDPP - Choke line friction loss Drill string volume

Circulate to fill annulus with kill mud FCP - - Annulus Volume

thers formulas used in Driller's Method: