INJECTION PROFILE MODIFICATION IN A HOT, DEEP MINNELUSA WATER INJECTION PROJECT

Jr., Lyle A. Johnson

Western Research Institute (United States)

关键词: Modifications;    Sweep Efficiency;    02 Petroleum;    Oil Fields;    Economics;   

DOI  :  10.2172/822150
RP-ID  :  NONE
RP-ID  :  FC26-98FT40323
RP-ID  :  822150

美国|英语

来源: UNT Digital Library

【 摘 要 】

As oil fields in the United States age, production enhancements and modifications will be needed to increase production from deeper and hotter oil reservoirs. New techniques and products must be tested in these areas before industry will adapt them as common practice. The Minnelusa fields of northeastern Wyoming are relatively small, deep, hot fields that have been developed in the past ten to twenty years. As part of the development, operators have established waterfloods early in the life of the fields to maximize cumulative oil production. However, channeling between injectors and producers does occur and can lead to excessive water production and bypassed oil left in the reservoir. The project evaluated the use of a recently developed, high-temperature polymer to modify the injection profiles in a waterflood project in a high-temperature reservoir. The field is the Hawk Point field in Campbell County, Wyoming. The field was discovered in 1986 and initially consisted of eight producing wells with an average depth of 11,500 feet and a temperature of 260 F (127 C). The polymer system was designed to plug the higher permeable channels and fractures to provide better conformance, i.e. sweep efficiency, for the waterflood. The project used a multi-well system to evaluate the treatment. Injection profile logging was used to evaluate the injection wells both before and after the polymer treatment. The treatment program was conducted in January 2000 with a treatment of the four injection wells. The treatment sizes varied between 500 bbl and 3,918 bbl at a maximum allowable pressure of 1,700 psig. Injection in three of the wells was conducted as planned. However, the injection in the fourth well was limited to 574 bbl instead of the planned 3,750 bbl because of a rapid increase in injection pressure, even at lower than planned injection rates. Following completion of polymer placement, the injection system was not started for approximately one week to permit the gel to set. The system then returned to operation as before the test with no major change in the fieldwide injection. The injection and production rates for the field were monitored for approximately one year to give the production side of the system time to stabilize. The polymer treatment conducted on the injection wells in Hawk Point is believed to be the largest treatment of a hot, deep reservoir to date. These injection well treatments did produce some change in the injection profile of the injection wells. However, it is very disappointing that there was no significant improvement in the performance of the field. There was no noticeable reduction in the water production, the water-oil ratio (WOR), or an increase in oil production. The cosponsor has determined that the field is currently at its economic limit because of the high cost of this deep operation and the continual downhole problems. A restructuring of the injection-production pattern is presently being done to prolong the life of the field.