- Lambda capillary pressure @model
- Laminar fluid flow
- Laminar Inertial Turbulent IPR @ model
- Land allocation
- Landscape Exploration Survey
- Lateral Logging (LL)
- Late Time Response = LTR
- lb/ft3 (density)
- Leak
- Leak Detection = LD
- Lederer-Roegiers viscosity blending equation
- Ledger (Finance)
- Lee-Gonzalez-Eakin (1966) gas viscosity correlation @model = LGE
- Legal Entity
- Length (physical property)
- Leverett J-function capillary pressure @model
- LFM – Lithofacies Modelling
- lg
- Liability (Finance)
- Lift Curves @model
- Lift mechanism
- Lift optimisation
- Lighthill equation
- Light Oil (fluid composition)
- Limestone
- Limited entry well
- Limited entry well pressure diffusion @model
- Linear Composite Model
- Linear-flow pressure diffusion
- Linear Flow Pressure Diffusion @model
- Linear Fluid Dynamics
- Linear Fluid Flow
- Linear newtonian single-phase pressure diffusion @model
- Linear PDE @math
- Linear Perrine multi-phase diffusion @model
- Linear Perrine multi-phase diffusion @model derivation
- Liner (LNR)
- Liquid (state of matter)
- Liquid Control
- Liquid Control (Reservoir Flow Modelling)
- Liquid production rate = qL
- Liquid Quality Line
- Liquid specific gravity = yL
- Liquid Surface Productivity Index
- Liquid viscosity @model
- Litho-Density Tool
- Lithofacial Index (LFI)
- Lithofacies log @model
- Lithological facies (lithofacies)
- Lithosphere
- Lithostatic Pressure
- LIT IPR @ model
- Live oil (chemical substance)
- ln
- Loan (Finance)
- Loan Body
- Loan-in (Finance)
- Loan-out (Finance)
- Local Calendar Time = LCT
- Local Grid Refinement (LGR) @model
- Log (well logging)
- Logarithmic Derivative @model
- Logarithmic Derivative = p'
- Log Derivative = p'
- Logging Pass
- Logging Reference Elevation
- Logging Reference Point
- Logic
- Long Fracture
- Long-Term Asset (Finance)
- Long-Term Intangible Asset (Finance)
- LSPD (Line Speed)
- PADE IPR @ model
- Pound = lbm
- Pressure Line Source Solution (LSS) @model
- Short Fracture
- Supercritical Fluid = SCF (state of matter)