ما هو الماسب وطريقه حسابه-MAASP In Drilling Definition, Calculations

-conditioned control operations the maximum permissible borehole fluid pressure at the covering shoe is typically considered to be the critical factor, grounded on the supposition that the weakest conformation is at the shoe. For prac­tical purposes, the corresponding pressure at the face( Drilling MAASP or Maximum permissible annular face pressure) is calculated through specific formulas and used during well-conditioned control operations.

MAASP description

The MAASP is the maximum pressure that can be allowed to develop at the face before the fracture pressure of the conformation just below the covering shoe is exceeded. Flash back that an increase in the annulus pressure at the face will mean that the pressures along the entire wellbore are adding also. typically the weakest point in a drilled well is the loftiest point in the open hole section( i.e. at the former covering shoe).

In other words, the Maximum Allowable Annular Surface Pressure – MAASP – when drilling ahead is the outside closed- in( not circulating) pressure that can be applied to the annular( drill pipe x BOP mound) at the face before the conformation just below the covering shoe will start to fracture( leak- off).

Why MAASP Is important?

During the well-conditioned control operation, it's important that the pressure isn't allowed to exceed the fracture grade at this weakest point. The fracture pressure of the conformation just below the covering shoe will be available from leak- off tests carried out after the covering was set. If no leak- off test was carried out an estimate can be made by taking a chance of the minimal geostatic grade for that depth.

Simple Considerations About Maximum Allowable Annular Surface Pressure

If an affluence occurs( check further about kick warning signs) and the well is killed with a kill slush by drillmaster’s system or stay and weight system this computation should be repeated to determine the new MAASP.

The MAASP shouldn't exceed 70 of the containing burst resistance.

Some control panels of ever controlled chokes have an automatic MAASP control point which doesn't allow the choke pressure Pch to exceed the pre­ set MAASP. When this point is used in situations whereby MAASP should be exceeded, for case when top affluence is formerly inside the covering shoe, further affluence is allowed to enter the hole unnecessarily which may lead to worsening situations. It's recommended not to use this point, but to acclimate the ever controlled choke( s) manually from the control panel.

MAASP computations

The MAASP can be determined from the following equation MAASP = Maximum permissible pressure at the conformation just below the shoe minus the Hydrostatic Pressure of slush at the conformation just below the shoe.

MAASP is typically calculated incontinently after performing a leak- off test and is also acclimated whenever slush viscosity is changed. Data from leak- off tests are combined with the current drilling fluid grade to induce the MAASP value. Given a known drilling fluid grade it's possible to express the conformation Strength as a Maximum Allowable Annular Surface Pressure( MAASP) that may be applied in addition to the fluid column before the conformation strength pressure is exceeded. This can be calculated as

MAASP = Dshoe x( EMMG- ρfluid)
EMMG : Equivalent Maximum Mud Gradient can be calculated from the following equation