Gas Lift Design Calculator

Gas lift is one of the most widely used artificial lift methods in the oil and gas industry, employed in approximately 10% of all producing wells worldwide. The technique works by injecting high-pressure gas into the production tubing through a series of gas lift valves installed at calculated depths along the tubing string. This injected gas reduces the hydrostatic gradient of the fluid column in the tubing, thereby lowering the flowing bottomhole pressure and increasing the production rate from the reservoir.

The design of a gas lift installation centers on determining the optimal valve spacing — the depths at which gas lift valves are placed in the tubing string. The graphical method, also known as the pressure traverse method, is the most common approach. It works by plotting pressure versus depth for the injection gas column (casing side), the kill fluid column used during initial unloading, and the operating fluid gradient that exists during steady-state production. Valve positions are determined by the intersections of these pressure lines, accounting for a transfer pressure drop at each valve to ensure proper unloading sequencing.

Injection Pressure Operated (IPO) valves are the most commonly used valve type. They open and close based on the casing (injection) pressure, with each successively deeper valve set to open at a slightly lower pressure than the one above it. This ensures that during the unloading process — when the kill fluid is displaced from the wellbore after initial installation — each valve opens in sequence from top to bottom until the operating valve is reached. Once the well is unloaded and producing, only the deepest (operating) valve remains open, while all upper unloading valves are closed.

Key design parameters include the surface injection pressure (determined by the available compressor capacity), the kill fluid gradient (heavier than the production fluid, used to control the well during workover), the transfer pressure drop per valve (typically 25-75 psi, which ensures proper valve sequencing), and the productivity index (PI) of the well. The PI, combined with the Vogel IPR relationship for wells below bubble point, determines how much production increase can be expected for a given reduction in bottomhole pressure.

This calculator implements the simplified graphical method for IPO valve gas lift design. It computes valve depths, the injection and tubing pressures at each valve, and estimates the expected production rate and required injection gas volume. All calculations run entirely in your browser — no data is sent to any server. For detailed gas lift optimization studies, including transient modeling and multi-well gas allocation, contact Groundwork Analytics.