Oil and Gas Wastewater Treatment

Characteristics of oil and gas wastewater treatment

Non-recyclable waste liquids produced during the development of the oil and gas, including drilling wastewater, acidified waste liquid and fracturing waste liquid.

The drilling wastewater in the oil and gas wastewater has the characteristics of high suspended solid content, high chroma, high COD value and difficult to degrade. Drilling wastewater include abandoned mud; loss of mud and debris from start-up and drill-down operations; flushing fluid for surface equipment and drilling tools; domestic sewage from wellsite, etc. The main pollutants are suspended solids, heavy metals, oils, phenols, sulfides, etc. These compositions and concentrations are different at each stage of operation.

The acidified waste liquid in the oil and gas wastewater has the characteristics of high Clˉcontent, high COD value, high salinity and difficulty in treatment. Acidification is an important means to improve the production of oil and natural gas or to repair depleted wells. The most commonly used acid in the acidification process is hydrochloric acid and acid.

The Fracturing waste liquid in the oil and gas wastewater has the characteristics of large viscosity, high suspended solid content, high COD value and difficult treatment. The fracturing fluid consists of cross-linking reagent, thickening reagent, clay stabilizing reagent, buffering reagent, tea bacteria reagent and assisting and displacing reagent. Fracturing is an important means of increasing production in oil, gas and water wells.

Oil and gas wastewater treatment

Process

Collecting oil and gas drilling wastewater into the EQ tank — Flocculation and clarifiers — Filtered with quartz sand — Filtered with activated carbon — Filtered with precision filter — Membrane Ultrafiltration — Reverse Osmosis System.