Changlu Oilfield in Dagang is HPHT trouble area, complicated formation condition, deep reservoir depth, multipressure layer system, high and low pressure formation lying together, complex lithologic character, small tectonic trap, easily occurring well collision, serious drift formation direction. It is in beach salt field area, so the wells in this oilfield belong to high pressure, high sulfur content and being in high hazard area. Due to the above mentioned difficulties, results in drilling operation in danger, low rate of penetration (ROP), long drilling period, which restrict development speed in this area, the key problems to be resolved are that how to decline drilling hazard, enhance ROP and control development costs. Aimed at the problems, it is on the base of safely drilling, optimizing drilling design and implementing advance drilling technology, especially in the block, popularized and applied navigation drilling system(NDS) and MWD, as well as in the light of geologic characteristic, optimized special screw drill and PDC bit, improved development speed, compared with finished well in the same block, general enhancing ROP reached 60%, ROP improved 75%, monthly drilling rate enhanced 26%, drilling period reduced 24%, occurrence rate of complicated accident was only 0.35%, the effect of enhancing drilling rate in safety condition is better.
Changlu Oilfield in dagang was put in exploration in 1992, and brought into production in 1995, due to complicated geologic condition, frequently occurred drilling accidents, oil production costs per ton affected the rate of new wells development. In 2003, it was placed on the management of non-producing tight block, and tried to the new method to implement oil development.