Research On The Third Infill Drilling Program In Eastern Part Of SZ Development Area

The development in Eastern Part of SZ area was put into production in 1960, during which the measures with respect to the first and second infill drilling were taken repectively. Up to now, the developing area has entered into late production period with high water cut, with water cut increasing and production rapidly declining, and developing results become more and more unsatisfying. Especially in 1985, after the casing damage wells with the first infill drilling has been closed, the relationship between injection and production was not complete even though the second infill drilling program had been conducted. The sweeping extent of water flooding only occupied 86.3% and the recovering rates for different formations were quite different, so the third infill drilling program was performed in 2000. With the third infill drilling, production decline rate and water cut increasing rate have been controlled and the development results have been greatly improved in recent years. Meanwhile, based on water injection among layer-by-layer and structure adjustment of produced fluids, the developing results in other areas have also been revitalized, and the oil recovery by water injection has been enhanced, which will offer instruction and experiences for other areas'third infill drilling programs and comprehensive adjustments.The research on the third infill drilling and development adjustment indicates that the sweep extent by water flooding has increased by 8.0%, including 10.1% for thin and low productivity zones and 7.8% for untablenated reserves. And recovering rate of the area has enhanced by 4.0% with 12.3% and 4.9% repectively for poor reservoirs and untablenated reserves. The well patterns with the third infill drilling not only control production decline and water cut climbing, but improve development results of original well patterns, resulting in annual water cut reducing by 0.9% and production decline per year decreasing by 2.62%. Based on performance curves and numerical simulation analysis, the third infill drilling makes the recoverable reserves increased by 34.85×104t and the oil recovery enhanced by 1.02%.