Research And Application On Enhancing The Cementing Quality Technology Of The Tertiary Infilling Adjustment Well

This dissertation focuses on the cementation mechanism of cementing sheath, the actual problem in the spot and the basic analysis of the sealing system of the cementing wreath. In addition, this paper includes the following content: expounding the possible states of cementing sheath system in the well bore, offering the conditions of the cementing sheath and ensuring some basic factors that influences the cementing sheath. So far, we have got some new knowledge which is about the function of the mud-cake in the cementing sheath, the consolidation and sealing problem of the interlayer and the cementing quality problem of the high-pressure-layer and low-pressure-layer from the experiment of cement-sheath property. Meanwhile we also got some new understanding of how to get a further improvement of the sealing quality of cementing-sheath. What we have done is the foundation for the further researches. The target of the tertiary infilling well of Daqing oil-filed is the thin-poor oil-layers. The outstanding features of these layers are thin interlayer, poor properties, low permeability and interlayer diversity. Therefore, we suggest that highly desires of cementing quality be needed to tertiary infilling well. That's to say, all thin layer must be cemented well and the cement cementation-factor of the perforation interval must be greater or equal to 0.8. At present, sonic-logging of the cementing quality, especially delaying sonic-logging doesn't meet completely the demand of the oil-field exploitation. Which means that we must abandoned some oil-layers for the cementing quality is beyond our request. This influences directly to the tertiary infilling well. According to the experiment of tertiary infilling in the spot and the summary of the present technical measures, we have attained new technique. So the cementing quality of tertiary infilling well can be approved and the purpose of tertiary infilling also can be assured. In addition, this paper also discusses the technique which should be used in cementing process under the condition of different formation pressure. This is a necessary technical preparation for large scale tertiary infilling drilling and cementing.