Drilling and completion techniques of cross-block ladder horizontal wells: a case of Well Y3p9

Yong’an block of Shengli Oilfield is a typical small complex fault block oil reservoir. In order to explore the potential of this kind of reservoir further, a cross-block ladder horizontal well is used on the basis of recognizing faults, and the remaining oil in different faults is produced by one well. By this method, the recovery is improved and the drilling cost is decreased. The paper analyzes the reservoir characteristics of Yong’an block and illustrates the difficulties for drilling and completion of this well, on the basis of which it introduces the drilling and completion techniques of the first cross-block ladder horizontal well of Shengli Oilfield, Well Y3p9. Geosteering technique and seismic cross section are combined to determine the fault location and to accurately control the well trajectory to pass through faults and dig into another oil layer. Drilling and completion integrated technique and plastic micro-expansion slurry are taken to greatly increase the cementing quality of ladder horizontal wells. This well has been successfully drilled and produced, which proves the cross-block ladder horizontal well can improve the recovery ratio of fault block reservoir, and has promotional value.