THEORETICAL STUDIES OF HEAT AND MOISTURE TRANSFER IN A POROUS COARSE-DISPERSED MEDIUM OF A CRYOGENIC-GRAVEL FILTER ELEMENT IN THE PRESENCE OF PHASE TRANSITIONS

Abstract

The objective of this work is to advance the theory for enhancing the efficiency of gravel pack completion technology for oil and gas wells. This is achieved by pre-consolidating the gravel material into solid blocks at the surface and subsequently disaggregating them in the well's bottomhole zone. The disaggregation process is facilitated by utilizing the effect of an inverse, two-phase transition of the state of aggregation in a water-based mineral binder.

The research is based on a theoretical analysis of heat and mass transfer within a porous, coarse-grained, water-saturated, cryogenic-gravel filter system in the presence of phase transitions. Mathematical models, particularly Stefan problems, are employed to describe the principles of heat transfer in a porous, water-saturated medium.

This study deepens the understanding of the thermophysical and mass-exchange characteristics of porous, water-saturated materials at low temperatures and in the presence of phase transitions. Dependencies of thermophysical properties (heat capacity, thermal conductivity) on temperature have been established, accounting for the presence of bound and free water, as well as phase transformations. This enables more accurate modeling of the behavior of cryogenic-gravel filters.

The proposed concept of utilizing the inverse, two-phase transition of the state of aggregation in a water-based mineral binder under the cyclic influence of sub-zero and positive temperatures holds potential for developing new technologies to manufacture high-quality gravel filters at the surface. This approach could solve the problem of void formation in gravel packs, which leads to well sanding and equipment failure.