Prediction For Favorable Area Of Gaotaizi Reservoirs In Qian102Block, Songliao Basin

Qian102block belongs to Songliao Basin Changling sag–Qian’an structurenose ramp area, has an area of about9.65km2. The block has entered the early stage ofdevelopment. Due to the unclear understanding of the geological characteristics of thereservoir, the prediction of favorable block was inaccurate. This paper takes the39and40layer in the main reservoir of Gaotaizi as the research object, with theapplication of seismic data interpretation techniques, coherent volume interpretation,reservoir prediction technology, focusing on structure interpretation, sedimentarymicrofacies analysis, division and contrast of small layers and sand distributionprediction to achieve forecasting for favorable exploration areas. The mainachievements and acquaintances are as follows.1. This paper takes structural interpretation techniques to implement top surfacemorphology of the main reservoir of Qian102block. Controlled by the structuralsetting, the overall performance of the block was a slope which presented theeast-high and west-low feature. The block was divided into west exploration area andeast zone by No.4and No.5faults.2. Use of logging, seismic attribute data, based on the contrast of small layer, itcan be included that the block mainly developed delta front subfacies, including thesubaqueous distributary channel, mouth bar and frontal sheet sand. The39singlelayer mainly developed3subaqueous distributary channels and was with large areaand stable mouth bar, while the40single layer mainly developed subaqueousdistributary channel and was with rare mouth bar, the sand was transitioned to mudnorthward.3. In this paper, seismic attribute analysis techniques was applied to thereservoir prediction. Based on the actual sandstone thickness of the wells in the east,the result of the prediction shows that the west exploratory area has deep large sand.Besides, the predicted sandstone thickness of the Q102-11-2well area was7~9.5m.Compared with the actual sandstone thickness of typical wells, the predictedresult was believable.4. Based on the geological characteristics of the39and40single layers, theobjective evaluation and reservoir prediction were achieved, which indicates that thesands are with stable distribution and great heterogeneity, but with high potential.Based on comprehensive analysis of the reservoir control factors, two favorableblocks and two appraisal wells were proposed in the western exploration area.