The Research Of Gas Bearing Reservoir Forecast For Wang Jiang Tun Gas Field

Gas bearing reservoir forecast is an important topic during reserves'evaluating and developing. The technology can be divided roughly into seismic inversion and seismic attribute analyze. Through this technology, sand's plane distribution and the relation of sand and discordogenic fault can be described precisely. Especially gas-bearing sand's plane distribution is the key to acquire high-yield gas well.FY reservoir of Wang Jia Tun gas field develops small sands and these sands are distributed complicated. Under present well pattern, which keeps 800-1000m well space, about 70% sands are not connected. For this reason, there are quite big difference from proved reserves and dynamic well control reserves. The write utilizes geology, seismic, and well logging data on the basis of 3-D seismic information of Wang Jia Tun gas field to forecast its FY reserves. First, a few kinds of wavelet estimation technologies are used to calculate difference seismic waves, difference frequency are used to make synthetic seismogram. Geologic horizons are calibrated exactly through comparing these data with seismic facies map and seismic waveform of near well bore zone. Then horizontal chip and some other technology which provided by Landmark workstation are used to interpret fine structure of faults and horizons. On the basis of these interpretations, Jason software is used to make sparse spike inversion and reserve parameters inversion. Through treating wave impedance data, which from above inversion, SP data and gamma data volume, related attribution are extracted, and the plane distribution laws of reserve feature, for example sand, permeable sand, average sand porosity and average sand impedance, are acquired. Moreover, Seismic attribution analysis, feature parameter extraction, cluster analysis are all used to forecast oil or gas-bearing sands, the write predicts favorable area for Wang Jia Tun gas field and points out the drilling objects.