Leif Hinderaker, SPE, Norwegian Petroleum Directorate, Rolf H. Utseth, SPE, Statoil, Odd Steve Hustad and Idar Akervoll, SPE, IKU Petroleum Research, Mariann Dalland, Bjorn Arne Kvanvik, Tor Austad, and John Eirik Paulsen, SPE, RF-Rogaland Research. Abstract RUTH (1992-1995) was a four year Norwegian research program on improved oil recovery funded by Norwegian authorities and 18 participating oil companies. This paper describes how the program was organized and highlights the main results. Research was performed within six main themes: Gas flooding, combined gas-water injection including WAG, foam, polymer-gels, surfactant flooding, and microbial method. Applications in Norwegian fields are discussed with special focus on field pilot tests. The program contributed to establish a pilot-activity on three new methods, WAG, foam, and polymer-gel, on the Norwegian continental shelf. Introduction An important goal for Norwegian petroleum policy has been to secure the best possible exploitation of the petroleum resources. The initiation and implementation of IOR R&D programs have been an essential part of the strategy to reach this goal. Several major Norwegian IOR programs have therefore been initiated since the nineteen eighties. These are listed on Table 1. The Joint Chalk Research program, dedicated to improving hydrocarbon production from Norwegian and Danish chalk fields, was launched in 1982 on the initiative of Norwegian and Danish authorities. The state sponsored SPOR program, which was carried out during 1985 through 1991, focused on IOR and EOR methods, and had as its main goal to build a national Norwegian IOR expertise. Two follow-up programs were initiated after SPOR: The PROFIT program, concentrating on "Reservoir Characterization" and "Near Well Flow", and RUTH. PROFIT was a collaborative program between 13 oil companies and the Norwegian Petroleum Directorate (NPD). About 50 million USD have been invested in these programs, including RUTH. RUTH (Reservoir Utilization through advanced Technological Help) was a cooperative IOR effort conducted by the Research Council of Norway, the Norwegian Petroleum Directorate, Norwegian research organizations, and 18 oil companies. The total program budget was 106 million NOK. The Research Council of Norway funded 55 million NOK, and 51 million NOK was funded by the participating oil companies (1 USD is about 6.50 NOK). The program lasted 4 years (1992-1995), and a total of 32 projects were performed. RUTH aimed at following tip the research topics included in the SPOR program which were not conducted by other programs, and to include new subjects of strategic importance. The main objectives were:–Contribute to increase oil recovery from sandstone and chalk reservoirs on the Norwegian continental shelf by 300 million Sm3.–Meet the authorities' specific and long-term requirements for research on advanced oil recovery.–Help Norwegian research groups to further develop an internationally recognized expertise that can be of use to the oil companies. Additional objectives were to concentrate on applied research that is related to advanced recovery methods and to help qualify advanced technology by means of field tests. Of the three main objectives, we believe the first objective will be reached through the use of the developed technologies, and that the other two objectives have been met. P. 251

No abstract

No abstract

The goal of any petroleum producing country is to maximise the long-term social value of the hydrocarbon assets. To protect society's interests in development and operation of oil and gas fields, the Norwegian authorities have established frameworks for these activities, which are intended to ensure that the companies makes decisions that are also beneficial to the society at large. In Norway the Norwegian Petroleum Directorate (NPD) has the authority to monitor the development of the different oil and gas fields and to ensure that the fields are being produced in accordance with best practice reflected in regulations and the framework established. As for use of associated gas the regulation pertaining to proper utilization of the petroleum resources has been of paramount importance. In the regulations it is stated that flaring of petroleum is not allowed, unless in quantities needed for safe operation. From day one the oil companies thus had to find a proper way of utilizing the associated gas. In most cases the gas was transported in pipelines and sold to the market, but in some cases there was no pipeline available and re-injection into the reservoir was the only option. Improved recovery has been and still is of great concern for Norwegian authorities. Several initiatives have been made to evaluate the possibilities for improving oil recovery. The results of gas injection have been studied together with other methods for enhancing the oil recovery. For the Norwegian oil fields pressure maintenance by use of associated gas has proved to be very successful. By the end of 2009 and since the oil production started on the Norwegian Continental Shelf in 1971 a total of more than 3526 million Sm3 of oil and 2138 billion Sm3 of gas has been produced. Most of the gas produced has been exported to the European market. Some gas has been used as fuel on the platforms and for transportation purposes and a small amount has been used in Norway as feed-stock for petrochemical plants. Due to strict regulations and economical incentives just a minor part has been flared. However it is reported that gas in the order of 595 billion Sm3 has been re-injected into the reservoirs to sustain pressure and to enhance oil recovery. The average oil recovery factor for fields in production today is estimated to be 46%. It has been estimated that re-injection of gas so far has yielded an extra oil recovery of between 240 and 270 million Sm3 oil and condensate compared to the case without gas injection. If existing plans for further gas injection are executed, the total gains are in the range 320 to 360 extra million Sm3 oil and condensate.

No abstract