Volcanic Rocks Reservoir Prediction Method And Its Application In Malang Area

Malang area has been a breakthrough in volcanic rocks in Carboniferous and became one ofthe main oil-producing areas in Tuha Basin in the past few years. But because volcanic rocksanisotropy is strong and the lateral variation of favorable reservoir is fast in the study area, we hasstill not a effective method to predict reservoir of volcanic rocks, which has severely restricted theoil field exploration and production.In this study, fine structure interpretation has been completed by using the technologies ofLandmark interpretation system based on3D connection data of Malang area. Many sets of seismicreflections have been interpreted including the bottom of Jurassic system, the bottom of Triassicsystem, Fm. Lucaogou and Fm. Tiaohu of Permian, Fm. Kalagang and Fm. Haerjiawu ofCarboniferous. Through the interpretation, the characteristics of faults and structures have beenanalyzed and the top of oil-producing zones have been interpreted, and intermittent surface of avolcanic eruption and erosion surface were fine portrayed.On the base of accurate horizon interpretation, we study the weathering-leaching reservoir ofFm. Kalagang and inner reservoir of Fm. Haerjiawu in Carboniferous. The Kalagang weatheringand leaching-type reservoir is mainly affected by facies control of the degree of weathering andleaching, developed fractures and other factors, its physical aspect to the changes caused bychanges in such reservoir logging and geophysical response characteristics；HarJiawu group of"insider" reservoir is mainly controlled by facies, cracks, source rocks and other factors.Reservoirprediction around the source rocks in the implementation of the basis of its favorable faciesdistribution of fracture prediction. By dissecting the volcanic mechanism and combining with thedivision of volcanic rocks in the single well facies and the plane distribution law of seismic facies,the development of favorable facies belt can be predicted, which has laid a foundation for reservoirprediction. On this basis,By using the frequency attenuation gradient of seismic attributes,instantaneous dip angle detection, edge detection and coherence to identify the fractures ofvolcanic rock reservoirs, the developed fracture belts of high density were predicted effectively.And integrated with the post-stack inversion and pre-stack inversion, the distribution of volcanicrock reservoirs of Fm. Kalagang and Fm. Haerjiawu were predicted.Carboniferous volcanic effective reservoir Santanghu Basin volcanic reservoir predictiontechnique applied research to further improve the prediction accuracy, the results show that themethod has broad application prospects and promotion.