Date of Award
Master of Science (MS)
Dr. Maysam Pournik
Dr. Karen Lozano
Dr. Horacio Vasquez
Matrix Acidizing is defined as a well stimulation technique in which the acid is injected into the formation with the purpose of dissolving the minerals present and thus enhancing the permeability of the formation and facilitating the extraction of oil and/or gas from the formation. The primary goal of acid diversion is the creation of wormholes and ramification paths that allow the fluid to flow from the higher to the lower permeability zones of the limestones, sandstones or carbonate reservoirs. Naturally, as the injected acid will follow vugs, fractures and pores, HCl is used because of its quick reaction and fast limestone dissolution. Matrix acidizing is one of the most utilized well stimulation techniques because of its low cost when compared to other techniques. It is known that there are four main parameters affecting the test performance: Injection rate of the acid, the reaction type, the heterogeneity, and the calcite concentration.
To conduct experiments simulating real field conditions, a core flooding laboratory setup was developed. Acid is injected at high pressures using a continuous flow syringe pump. The acid and the brine are injected at pressures below the fracture pressure, this will remove any existing damage in the formation, restore and improve the well productivity. Furthermore, to simulate the overburden pressure, self-weight of the soil or hydrostatic pressure, an overburden pressure pump was added. Finally, it is also important to add the back pressure exerted by the well, this with the use of a backpressure regulator.
The main goal of the laboratory development is to study, analyze and understand the optimum conditions for wormhole creation. Multiple parameters such as injection rate, temperature, injection pressure will be studied and tested to find optimum parameters.
The core flooding apparatus was design to test at pressures as high as 5000 psi, stainless steel tubing, valves and fittings were utilized in order to support the corrosive nature of the Hydrochloric Acid. As temperature plays an important role in matrix acidizing, a heating tape around the core holder was added to perform tests at different temperatures. A compact design was developed as one of the main goals is to reduce the length of the tubing and thus reduce the amount of fluid loss by the pipes.
Hernandez Zuniga, Antonio, "Development of a Compact Core Flooding Apparatus for Matrix Acidizing Applications" (2021). Theses and Dissertations - UTRGV. 889.