Font Size: a A A

Sandbody Architecture Of Overlapping Shallow Water Detla And Its Implication To The Development

Posted on:2013-08-19Degree:MasterType:Thesis
Country:ChinaCandidate:W CaiFull Text:PDF
GTID:2230330374476727Subject:Mineral prospecting and exploration
Abstract/Summary:PDF Full Text Request
The study of continental shallow water delta depositional systems is currently the hot research of sedimentology. However,the study of the structure of sandstone reservoirs in the shallow water depositional systems is still not deep enough,and have not yet very mature understanding and research results.The deposition model that in deeper water conditions have certain differences with the shallow water delta characteristics.According to analysis of the internal structure of reservoir model,it is bound difficult to rebuild the internal structure characteristics of sand body, and greatly restricting the understanding of the shallow water delta reservoir. Adopting new methods and new models to re-understand internal structure of the reservoir sand bodies and fine portraying the internal structure of the shallow water delta has become an urgent need in the development of such delta.The Daqing xing six main layer is a typical shallow water delta sand body,its sand bodies Characteristics is significantly different to the shallow water delta,and is difficult to compare by traditional way. How to create a fine stratigraphic framework and reconstruc internal structure of reservoirs has become the key to understand the distribution of remaining oil and improve oil recovery.By using Daqing xing six main layer as research objective,and the understanding of geological background and the sand deposition characteristics,and combined with exploration practice of daqing main layer and indoor deposition experiment,this paper puts forward shallow water delta depositional model and a new reservoir internal structure analysis method,and finely dissect xing six main layer, and rebuild the internal reservoir structure framework of delta on the basis of lobe. Under the new framework,the discussion of the oil and water movement characteristics and development of response characteristics of such delta reservoir have provide a new technical ideas for the development and adjustment of the area. In accordance with the above ideas, the main study in this thesis are shown as below:Firstly,investigating the geological background of xing six and identifing the development of the shallow water delta.The whole Songliao Basin is a large shallow water lake basin during the main layers deposition period,its terrain is very gentle slope on land and underwater and have not significant change into the lake before and after. The river energy is strong and controls the formation of the delta,which lead to the development of the multiple River-Delta sedimentary types. The main layer was the delte inner front facies in the yao period time,and the main deposition was the misfolding contiguous distributary channel sand body that was formed under the control of the multi-material source,which was banded, reservoir thickness and the existence forms was distributary channel complex.PI2-3distributed a large area of distributary channel sand body. PI1developed delta front sedimentary sand body.Secondly,under the surveys of delta depositional model,doing iindoor simulation experiments by the formation of the shallow water delta have reappear deposition process and the sand body distribution,which show that the overlapping shallow water delta is a model of the shallow water delta.The literature survey showed that there is a big difference between shallow water delta deposition and deeper water delta deposition,while the result of the indoor sedimentary simulation show that the advance and retreat of river in the different lake level is controlled by the accommodation space,its lateral swing result in mutual overlay of lobes in the process of the formation of shallow water delta, the shallow water delta complex was formation at the last. Such delta internal structure regards the foreset lobe as the basic unit and there is no unified triage system. So it is difficult to dissect and analyze the delta by means of traditional distributary channel and mouth bar model.Again,contrsting the shallow water delta by means of using foreset compared system, regarding single lobe as the basic unit and using the lobe complex as constraints, which reconstruct the stratigraphic framework and build the internal structure of delta sand body. Take dense well pattern thick oil in the area for example of this paper, establish the skeleton profile, using the thick reservoir top and end mudstone as benchmark, progradational overlapping lobe as basic unit, constructing the contrast profile by means of bottom pullout, using the combination of well logs to identify the composite flowers, Identify a single lobe by the return and the cycle of the curve changes, tracking the lobes in three-dimensional space, and determine the three-dimensional distribution of the lobe. Analyzing the space evolution of a single lobe by lobe superimposition on the basis of single profile comparisons and three-dimensional closed,which reappear the delta building process and reconstruct delta formation process. On the plane, analyzing the migration of a single lobe of delta and describing the structural characteristics of the delta combined with the morphology of the lobe. The single flower’s inner was difficult segments,and probable be formde by dot diffusion or linear extension. The front edge facies overlay made by the lobe. More than one flower emerged in the shape of the plot style。Finally,exploring the factors that affect the oil-water movement in the new delta reservoir framework,and specifying the percolation capacity determined by superimposition of the single lobe,contact between the lobes and preservation degree of mudstone on lobe contact position,which is the key that determine the oil-water movement. The understanding of the internal structure of the new delta sand body is significantly different from the original,which have provides a new direction and ideas for reunderstanding of the remaining oil.The reservoir framework is established by the based of superimposed shallow water delta model and take full account of the delta foreset process,which is completely different from the traditional delta that the framework is based on triage system. Connectivity between sand bodies is also different from traditional Delta,which is determined by the relationship between lobes within the framework.Thus,the proposition of this model and solutions will provide new technical ideas for the remaining oil analysis and development adjustment of such delta,and contribute to enhanced oil recovery.
Keywords/Search Tags:shallow water delta, sand body anatomical, laminated sand body, sedimentary model
PDF Full Text Request
Related items