Development and Qualification of a High-Pressure, High-Temperature Chemical Injection Valve

Abstract

As conventional oil and gas resources decline, interest in unexplored or underdeveloped areas has grown steadily in recent years. High-pressures and/or high-temperatures (HPHT) are the new normal when exploring these territories, posing tremendous challenges on almost all aspects from drilling to completion and production. One of these challenges is developing chemical injection systems with high integrity and reliability specifically for HPHT applications. The chemical injection systems provide precise wellbore chemistry management by pumping down chemicals via dedicated injection lines. Working principles of chemical injection systems for HPHT applications are not significantly different from those used under less-demanding well conditions; however, challenges remain due to harsh HPHT conditions that affect material and equipment performance. This paper presents the development and qualification of an HPHT chemical injection valve that is the key flow control device in a chemical injection system. The valve contains a pressure differential valve design that creates a "bubble-tight" seal between wellbore fluids and the surface, provides a constant flow rate, and eliminates valve cavitations. The valve was thoroughly tested at various temperatures, pressures and flow rates, and it withstood conditions representative of the most severe well environments. The design cycle was also shortened by integrating computational fluid dynamics (CFD) simulations into the design process and good agreement was achieved between the simulations and the experiments.