Study and Verification of a Physical Simulation System for Formation Pressure Testing while Drilling

Abstract

Based on a brief overview on the determination methods of formation pressure and their features, the major principle of formation pressure testing while drilling (FPTWD) and existing physical simulation systems was introduced, and the deficiency of the existing physical simulation systems was also discussed. A laboratory high-precision physical simulation system was therefore developed to simulate the downhole testing environment and testing process of FPTWD. The present experimental system was designed to endure pressures up to 20,000 psi, and the relative control accuracy of pressure is approximately 0.02% FS. Two kinds of man-made specimens with the permeability of 10–110 mD were used to test the pressure response and to verify the present physical simulation system. The debugging results indicated that the variation amplitude under the stable condition is approximately 0.07 psi, 0.08 psi, 0.11 psi, and 0.11 kN for the annular pressure, pore pressure, confining pressure, and thrust force, respectively. Thus, the high control accuracy is approximately ±1.0 psi under the stable conditions. The experimental results indicated that the pressure drawdown declines rapidly in the stage of withdrawing formation fluids and then recovers slowly. The pressure drop amplitude also decreases with permeability, while the pressure buildup amplitude increases with permeability. The tendency of pressure change is nearly the same for both the present and the previous systems, and the pressure curve of the present system is much smoother and better than that of the previous system. The relative error of explaining formation pressure is less than 1% and 4% for the present and the previous systems, respectively. In addition, this physical simulation system has important applications to verify the interpretation model, to analyze pressure response recorded by FPTWD tools, to test the capability and design of FPTWD tools, and to calibrate the formation pressure, formation parameters, and instrument factors.

Design method and application of accurate adjustment scheme for water injection wells around adjustment wells

“…However, during the drilling and completion of the infill adjustment well, affected by the surrounding geological conditions and injection-production wells, the formation pressure near the adjustment well may be in an overpressure or underpressure state, leading to complicated situations and accidents such as leakage and overflow. This can be seen from the pressure measurement while drilling data (Ma et al 2018;Peng et al 2021) (Fig. 1).…”

Application of GMDH model to predict pore pressure

“…Another tool that measures formation pressure is the Repeat Formation Tester (RFT), which is a routine tool in the petroleum industry (MacArthur et al, 2000;Matar et al, 2019;Jafarizadeh et al, 2022). But one of the reasons that has made the use of these tools problematic is that they are expensive and time-consuming to drive (Ma et al, 2018). As a result of such reports, which are generated using expensive tools, the determination and estimation of PP for specific depths are limited.…”

Study on Method of Determining the Safe Operation Window of Drilling Fluid Density with Credibility in Deep Igneous Rock Strata

“…Poor wellbore stability and narrow pressure window lead to complex downhole problems such as lost circulation and well collapse, which seriously restricts the high quality and fast drilling [5][6][7]. Drilling geological characteristic parameters (DGCP), mainly involving formation three-pressure and leakoff pressure, are the basic data reflecting the fluid and rock physical properties in the strata and the geological structure [8,9]. e accurate calculation of DGCP is an important premise to ensure the correct design of well structure and reasonable control of drilling fluid density [10][11][12].…”