An Integrated Laboratory Workflow for the Design of a Foam Pilot in Malaysia

An integrated laboratory workflow for the design of a foam pilot in Malaysia. Max Chabert (Rhodia), Lahcen Nabzar (IFPEN), Siti Rohaida, Pauziyah Hamid (Petronas PRSB). We present the laboratory feasibility study dedicated to the design of an enhanced water alternating gas (EWAG) process for a Malaysian oilfield. The field is currently submitted to produced gas injection, mainly consisting of CO2. We focus here on the design of a water soluble foaming surfactant formulation using advanced characterization methods and the evaluation of this formulation in corefloods experiments. On-field conditions make the design of a surfactant formulation particularly challenging, with a reservoir temperature of 100°C and only sea water available for foaming formulation injection. The ultimate goal of this design study is thus to obtain an industrially realistic formulation yielding stable foams in reservoir conditions (including in presence of oil) at an affordable price. We set-up a specific laboratory workflow to design a foaming surfactant formulation adapted to reservoir settings. An automated screening routine based on robotics was used at ambient and reservoir temperature to pre-select the most performing formulations for foam stabilization among more than 400 binary and ternary mixes. Formulations solubility maps were obtained using automated image analysis. Only formulations perfectly soluble in the window defined by injection and production waters salinities were retained for further testing. Selected formulations were then characterized for foam stabilization in reservoir pressure and temperature conditions using a high pressure variable volume view cell. Adsorption of the selected formulations on reservoir crushed rock was optimized by exploiting synergistic effects between surfactant families. A formulation yielding over 2 hours foam half-life in reservoir conditions with a static adsorption below 1 mg/g was obtained. This formulation was further characterized in petrophysics application tests using analog Berea sandstones and reservoir rocks. These tests were designed to mimic potential pilot conditions in terms of injection strategy, injection rate and gas composition. High values of mobility reduction factors were obtained, including in presence of residual oil. This set of results is a first step toward application of an enhanced WAG foam process.