0
RESEARCH PAPERS

# Fine-Scale Simulation of Sandstone Acidizing

[+] Author and Article Information
Chunlou Li

Department of Petroleum Engineering,  The University of Texas at Austin, 1 University Station, MC C0300, Austin, TX 78712

Tao Xie

Department of Petroleum Engineering,  The University of Texas at Austin, 1 University Station, MC C0300, Austin, TX 78712

Maysam Pournik

Department of Petroleum Engineering,  The University of Texas at Austin, 1 University Station, MC C0300, Austin, TX 78712

Ding Zhu

Department of Petroleum Engineering,  The University of Texas at Austin, 1 University Station, MC C0300, Austin, TX 78712

A. D. Hill

Department of Petroleum Engineering,  The University of Texas at Austin, 1 University Station, MC C0300, Austin, TX 78712

J. Energy Resour. Technol 127(3), 225-232 (Mar 31, 2005) (8 pages) doi:10.1115/1.1944027 History: Received August 31, 2004; Revised March 31, 2005

## Abstract

We have developed a fine-scale model of the sandstone core acid flooding process by solving acid and mineral balance equations for a fully three-dimensional flow field that changed as acidizing proceeded. The initial porosity and mineralogy field could be generated in a correlated manner in three dimensions; thus, a laminated sandstone could be simulated. The model has been used to simulate sandstone acidizing coreflood conditions, with a $1in.diam$ by $2in.$ long core represented by 8000 grid blocks, each having different initial properties. Results from this model show that the presence of small-scale heterogeneities in a sandstone has a dramatic impact on the acidizing process. Flow field heterogeneities cause acid to penetrate much farther into the formation than would occur if the rock were homogeneous, as is assumed by standard models. When the porosity was randomly distributed (sampled from a normal distribution), the acid penetrated up to twice as fast as in the homogeneous case. When the porosity field is highly correlated in the axial direction, which represents a laminated structure, acid penetrates very rapidly into the matrix along the high-permeability streaks, reaching the end of the simulated core as much as 17 times faster than for a homogeneous case.

<>

## Figures

Figure 1

The model gridding system

Figure 2

3D plot of random porosity distribution

Figure 3

Histogram of randomly distributed porosity

Figure 4

Correlated initial porosity distribution (strong correlation in x and y directions)

Figure 5

Δϕ for the base (homogeneous) case

Figure 6

HF concentration at 35PV, base case

Figure 7

Porosity distribution after 15PV, heterogeneous porosity and homogeneous mineralogy case

Figure 8

Δϕ distribution (Δϕ>0.02) for heterogeneous porosity and homogeneous mineralogy case

Figure 9

Δϕ for correlated porosity case (Δϕ>0.02)

Figure 10

HF concentration distribution after 5PV, correlated porosity case

Figure 11

Δϕ for correlated mineralogy and homogeneous porosity case

Figure 12

Permeability evolution for random porosity cases

Figure 13

Acid breakthrough volume for random porosity cases

Figure 14

Acid breakthrough volume for correlated porosity cases

Figure 15

Initial porosity field—channeling case

Figure 16

Porosity>0.4 indicating channeling

## Discussions

Some tools below are only available to our subscribers or users with an online account.

### Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related Proceedings Articles
Related eBook Content
Topic Collections