Is Publication of Emission Data Serious

Conclusions In almost any environmental report of oil companies one can find emission data of E&P activities. Apart from the enormous expenditure, caused by data acquisition, the quality of results is doubtful. Because of many different emission factors for calculation of harmful emissions only few limits are set to manipulation of results. In addition simply announcement of results offers no potential for appraisal of data. The first step to get a better data basis of possible environmental influence in hydrocarbon exploration and production are field measurements. The poster presented is focussed on measurements of methane concentrations in air. Methane is volatile and the best indicator for losses ore leaks in hydrocarbon production, especially in natural gas production. Enhanced methane concentrations (concentrations higher than the natural level of about 2 ppmv methane in air) are an indicator for several human made air pollution, e.g. rice or cattle cultivation, coal mining or natural gas production, but also can arise from other natural sources. The locally ground level of methane in air has therefore carefully to be checked before one starts with measurements of additional methane concentrations coming from hydrocarbon production. The following scheme of measurements was carried out: Description of the general situation of methane concentration in the atmosphere in the greatest hydrocarbon production area of OMV in Austria. This production area has an extension of about 150 square kilometres with about 300 gas and 800 oil wells. Long-time continuous measurements over a period of one month at three location were done. To get serious results the statistical distribution of wind direction in the production field was checked from meteorological data. Based on these results, the geographic locations were defined for the one month measurements. The first location was defined for the check of uninfluenced air flowing into the hydrocarbon production field. Uninfluenced air means without influence of any hydrocarbon production. The second location was sited on a geographical opposite point at the boarder of the production field, where the air leaves the area. The distance between location one and two is about 15 kilometres. The third point was located almost in the centre of the production field close to a gas storage plant and several gas and oil production wells. Methane concentrations were monitored in a mobile container for air pollution documentation. For detection a continuous measuring flame ionisation detector (FID) was used. Detection limit was 100 ppb methane in air. Samples were taken at a height of 3,5 meters from bottom. Result of the measurements: in general there was no influence on the concentration of methane downstream to detect. That means, that the natural level of about 2 ppmv methane in air at the ground is not influenced by all technical activities in the hydrocarbon production area. The result of step 1 must be proved by additional measurements at individual production facilities. Only with these measurements a clear statement of the influence of hydrocarbon production on the methane concentration in air is possible. There are different possibilities to get analytical data of methane concentrations resulting from leakage at a production site: e.g. housing of complete production facilities or wells, housing of individual valves or gauges, measuring of the concentration of methane at defined distances from a possible methane source (immission measurements). In this study was decided to make immission measurements of methane in the surrounding area of a production site / production well and to calculate with a meteorological model the source of methane emissions. The same mathematical model can also be used to calculate immission values from a known source of emission. Such calculations were made for several wells with different flow rates of methane.