Lecture Topic: Dynamic Modeling of Injectivity Evolution in Unconsolidated Formations

Lecturer: Professor Arash Dahi Taleghani

Lecture Time: December 23, 2019 (Monday), 3:00 p.m.

Location of Lecture: State Key Laboratory A403 Academic Report Hall

Organization of Lecturer: Pennsylvania State University

Abstract:

In this presentation, we look at injectivity changes of water injectors targeting unconsolidated formations as a result of erosion or channelization. In this situation, sand particles migrate from the formation matrix toward the wellbore and consequently affect the well performance and completion components like frac-packs or gravel-packs. To simulate this phenomenon, we use a model that decomposes the sand matrix into two different phases by means of volumetric fractions. The first phase consists of the immobile granular phase while the other is the fraction of grains that are detached from the matrix and carried away by the fluid. The ratio of these two phases evolves over time by means of erosion and deposition. Considering the fact that erosion is understood in its physical form as gradual destruction or diminution of the material, a model is needed to describe rock elastic and plastic properties during the mentioned destruction of solid skeleton of the rock. Hence, continuum damage mechanics is utilized in a coupled framework to model this problem. The results show how local porosity evolves over time around the wellbore by the formation of channels that enhance the flow, however, upon well shut-in, flowback induced by vertical communication or water hammer effect can bring a considerable amount of sand into the well and fills it up. A study of the effect of frac-packs which are typical completions for wells targeting poorly consolidated formations is performed to demonstrate potential damage of repetitive shut-ins on injectivity in these wells. The presented model appears as a robust tool to predict sand production for different completion systems to achieve more sustainable injection operations.

About the Lecturer:

Professor Arash Dahi Taleghani is a doctoral supervisor of petroleum and natural gas engineering at the Department of Energy and Mineral Engineering, Pennsylvania State University. He is mainly engaged in research in geology mechanics of oil reservoir and hydraulic fracturing. He has published more than 100 journal and conference papers in the field of petroleum engineering.

Host Organizations:

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation

SWPU Department of Science and Technology

School of Petroleum and Natural Gas Engineering