Study on exploitation techniques for bottom water pool with extremely thick reservoir in H616 block,Huanxiling oil field

H616 block is characterized by bottom water pool with extremely thick reservoir in Huanxiling oil field,with the thickness of individual stratum as 15～30 m and direct con- tact with bottom water.The block was exploited with steam stimulation in 1997 with individual well cycle as 2000 t and daily output as 24 t.The coning of bottom water resulted in rapid water flooding in wells (water flooded after 2-3 cy- cles).Study on the rapid water flooding of bottom water pool is performed in the following three aspects:the first, increasing the seepage power of oil field by horizontal well to relieve the differential pressure during production and to de- celerate the coning;the second,exploiting the remaining oil by side tracking well with large displacement;the third,es- tablishing manmade barrier to obstruct the coning of bottom water on the water- oil contact on the base of pool descrip- tion and digital analog.Since 1999,21 times of counter- measures as horizontal well,sidetracked hole and water blockage by manmade barrier were selected to solve the rapid water flooding of bottom water of H616 block in Huanxiling oil field with oil increasing amount of 59,941t.which not only effectively increases the recovery ratio of bottom water pool,but also makes a great breakthrough in dense oil devel- opment.