New method of predicting surge pressure apply to horizontal well based on casson flow*

Abstract

In order to predict the surge pressure caused in the horizontal well drilling process, a new simple and applicable method has been established. It is based on the general theory of hydrostatic drilling fluid mechanics, and specifically described the flowing physical model towards surge pressure in horizontal well annulus, taking the effect of string eccentricity on the flowing law of drilling fluid into consideration. According to the constitutive equation of casson-mode under one-dimensional steady flow and the equations of annular flow rate under different drill string working conditions, this paper introduced the flow rate computation models of axial laminar flow in eccentric annulus apply to horizontal well, of which the numerical model was calculated by the program called Mathematica, ultimately, a new model for surge pressure prediction towards each interval in horizontal well was put forward. Application examples indicated that it can solve questions easily and precisely, which presents important meaning of guidance to the safety control while horizontal well drilling

Numerical model for predicting the surge and swab pressures for yield-power-law fluids in an eccentric annulus

“…An analytical model for predicting the surge pressure in an eccentric annulus is based on the laminar flow of Casson fluids was reported (Sun et al, 2010), but the plug zone flow (or rather, the boundary condition t 0 ¼ 0) was ignored. An exact analytical model to predict the surge and swab pressures for BP fluids in an eccentric annulus was developed (Tang et al, 2014), but it also disregarded the yield stress as a boundary condition.…”

A New Model for Predicting Dynamic Surge Pressure in Gas and Drilling Mud Two‐Phase Flow during Tripping Operations

“…The fluid flow yielded by the movement of drill pipe is considered to be one-dimensional, compressible, and transient. In order to predict the surge pressure caused in the horizontal well drilling process, Sun et al [27] created models for predicting surge pressure based on the general theory of hydrostatic drilling mud mechanics and specifically described the flowing physical model towards surge pressure in horizontal wellbore by taking the effect of drill pipe eccentricity on the flowing law of drilling fluid into consideration. Lebele-Alawa and Oparadike [28] analyse the effects of surge pressure on pipe flow.…”