Study on Critical Drawdown Pressure of Sanding for Wellbore of Underground Gas Storage in a Depleted Gas Reservoir

Abstract

Accurately predicting the critical differential pressure (CDP) of sand production contributes to improving the peak-shaving capacity and ensuring safe operation of underground gas storage (UGS). The CDP of sanding production in the target wells of the UGS was predicted coupling laboratory tests, inversed analysis with well logging data and numerical simulations. The in-situ mechanical properties of rock were estimated by coupling the laboratory test results and well-logging data. The in-situ stress field of the target formation was then deduced through inversed analysis coupled finite element method (FEM) and genetic algorithm (GA), based on the existing known stress data and the seismic data of the measured points. Using the critical strain limit (CSL) of 5‰ as the sanding criterion of the wellbore, the CDPs of the gas production in the UGS were predicted, which was 5.59 MPa, 3.98 MPa, and 4.01 MPa for well #1, well #2 and well #3, when the pressure of the gas storage was 30 MPa, respectively. The simulation results showed good agreements with the field-measured benchmark data of well #2 and well #3. The effects of moisture contents (ranging from 10 to ~40%), and cycling times of gas injection and withdrawal (ranging from 40 to ~200 cycling times) on the critical differential pressure were simulated and analyzed. The results indicated that the CDP decreased with an increase of the moisture content and the cycling times. This study provides a reliable tool for the sanding prediction of the wellbore in the UGS.

Research advance of numerical simulation methods for sand production prediction of unconsolidated sandstone

“…This method uses the true triaxial stress chamber (TTSC) to simulate the single-hole sanding behavior under true triaxial stress and fluid flow conditions and is verified by the finite element software ABAQUS (Younessi et al, 2013). Studies suggest that there is a critical drawdown pressure difference to induce sand production in the sand producing area around the borehole (Song et al, 2022). The failure prediction under true triaxial stress state is more accurate than Drucker-Prager (Al-Ajmi and Zimmerman, 2005;Al-Ajmi and Zimmerman, 2006) and has a stronger correlation with the experimental results.…”

Experimental research on the effect caused by effective stress change in injection production capacity of carbonate reservoir

“…There is a correlation between porosity, permeability with effective stress. The pore volume and permeability of rocks decrease with the increase of the cycle of pressure reciprocating changes (Ranjith et al, 2013;Song et al, 2022). The natural gas in the UGS is stored and migrated in the fractures and pores of the reservoir, with the injection production of the UGS, the internal characteristics of the reservoir are also changing (Dake, 1983;Gobran et al, 1987;Economides and Nolte, 1989;Cosentino, 2001;Lucia et al, 2003;Jaeger et al, 2009;Lake, 2012;Ahmed, 2018) (Figure 4).…”

Critical drawdown pressure prediction for sanding production of underground gas storage in a depleted reservoir in China

“…In the multi‐cycling injection–production process, the sanding production with the high‐speed natural gas in the depleted oil and gas reservoir will erose the strings, valves, and other equipment. Many UGS in the depleted oil and gas reservoir have faced the engineering challenges of sanding production, such as Wen 96, Wen 23, Hutubi in China, 8 Redfield, Vincent, 9 Hillsboro 10 in America, Hajdúszoboszló, 11 Haidach 12 in Europe. Thus, a deep understanding of the sanding production in the depleted oil and gas reservoir contributes to maintaining the injection and production capacity of gas storage and the long‐term safety of the UGS.…”

“…Song et al accurately predicted CDP based on inversion results of numerical simulation of the geo‐stress in the target reservoir, combined with experiments and logging data. It showed that the depletion of reservoir pressure and the increase of water saturation will also lead to the decrease of CDP 8 . Thus, to guarantee the safe production, accurate prediction of the critical drawdown pressure (CDP) of UGS is necessary for predicting the sand production problems.…”

“…It showed that the depletion of reservoir pressure and the increase of water saturation will also lead to the decrease of CDP. 8 Thus, to guarantee the safe production, accurate prediction of the critical drawdown pressure (CDP) of UGS is necessary for predicting the sand production problems.…”