| Honghaoershute sag is one of the oil rich and old sags in Erlian basin, which belongs to Wunite depression in Erlian basin on the geological structure. On the south-east is border major fault connects with Da xing an ling uplift, and the northwest is a slope passes through Sunite uplift. The sag is typical single faulted sag. The whole strike of the sag is in the direction of east-north, with area about1100km2. Since the first drilled Hongcan1well in1993, there are83exploration wells with reserves have been drilled, there were13hydrocarbon entraps, and declared6hydrocarbon reservoirs, with proved OOIP reserves in2226×104t, probable OOIP reserves is223×104t. Although there were so many exploration outcomes, but there still existed phenomenon of disproportionate for the exploration. On the trough, the sub-sag in the east one is in high degree of exploration; and the middle and west sub-sags are in low degrees. On the reservoirs, the structural hydrocarbon reservoir is in high degree of exploration, but the composite hydrocarbon reservoir as lithologic and stratigraphic are in low degree. In the year of2010, the international advanced Trinity reservoir forming simulation software was first used in the sag, and quantified the dynamic migratory concentration reservoir forming from hydrocarbon Source-rock to trap, forecasted hydrocarbon resources and the total volume is about9620～17192×104t. Therefore, conversion rate of this sag is only18～32%,out under the old regions of conversion of Anan sag and Ji’ergelangtu sag in Erlian basin. So there has huge potential of exploration in this sag, especially in the low degree of exploration region and high accumulated areas located in middle trough’s bluff and ramp region and the new regions like volcanic rock and buried hills, they will be the next hydrocarbon exploration areas.From these years, along with the developing of new oil finding techniques, the innovating and breakthrough of new hydrocarbon exploration theories, Huabei oilfield tapped the latent power of reserves about old oil rich sags in Erlian basin, the petroleum geological comprehensive study of Honghaoershute sag is must imperative. In this paper, comprehensive on the data of3D seismic, formation, oil-generating, drilled wells, well testing of this sag, combined the new hydrocarbon exploration theory, new technique, study on the formation, oil-generating, sedimentary, reservoir and hydrocarbon accumulation and so on, by innovation thinking, established new, and further rational reservoir pattern, generalized hydrocarbon concentration and reservoir forming regular pattern, evaluated and optimized favorable exploration goals, they focused on the two belts of the middle trough and one new exploration and optimize the goals to find the scale reserves, and supply exploratory wells in order to realize hydrocarbon breakthrough, At the same time, offer on proposition next well location for exploration. There are some progresses and cognition we obtained in the course of study:1. There were14wells location passed in the final check up, and12of them have been put into drilling, there are6wells have the commercial oil flow among the12 wells. Well Hong37which located at the East wing of Haibei structure actic region of middle trough, has the daily production is20.14m3in the member of K1bt1in1674.0m-1683.0segment in general testing, it is the great breakthrough in exploration in the sag for the10years. Well Hong28drilled three oil layers and gain the daily production of2.24t and1.79t in andesite and glutenite separately in the lower K1ba and upper Klba, which located in the Baer anticline in the middle trough, it proved that Baer anticline is a favorable structure for hydrocarbon accumulation, so it enhanced the exploration value of arctic region, well Hong54located in the north slop of middle sub-sag, which has the daily production of1.84t in andesite reservoir in upper Klba, it showed that there are great exploration potential in the andesite reservoir in lower Klba, there are good display in slump fan reservoirs in well Hong67located in the rump of middle trough and there are11.8m/2bad oil layers in electric-log interpretation, the trap resource is480×104t, and show the well accumulation condition in the slump fan reservoir in the ramp slop.2.The reserves had been calculated in the main blocks including Blocks Hong54,Hong28, Hong37and Hong61, the value is1183×104t, Among them Blocks Hong54has two unites as andesite and sands and the OOIP is150×104t and180R104t, separately, Block Hong28has two units as Block Hong54and the total value is224X104t, Block Hong37has the OOIP value is379×104t with one units as K1bt1, as sands reservoirs with the OOIP value349×104t. And this program also implemented28good goals for the next exploration, and predict the trap resource is6890×104t.3. Using the Trinity reservoiring simulation software with popular in the world side to quantitative the expulsion and accumulation of this sag, and the total resource quantities is up to9620～17192×104t. So it is cognizance as the one of the oil-rich depression in Erlian basin again.4. By strata correlation and source rock analysis, there are two sets of mature source rocks as K1ba and K1bt1members in this sag, and the two layers’ drainages may occupied96.3%of the total drainages. It has be conferred that the member K1ba and K1bt1are the main explosive aim layers in this depression, and affected by the generating, migration and accumulation, the founded reservoirs and the good display all concentrated in these two layers.5. According to the data of litholigic assembled, the character of logging, sedimentary structure and seismic, the facies of lower Cretaceous system in Honghaoershute sag were consist of6facies and13sub-facies and33micro-facies, among them there5facies and10sub-facies are favorable explorative facies. 6. In the4different structure styles of the trough, because of different faulted composition and developmental characteristic and sedimentary facies characteristic, the different explosive area has different type hydrocarbon reservoir.7. Aimed at the main factors of this depression’s hydrocarbon exploration, comprehensive study, evaluation overall, optimizing the good goals, make recommendations for the next explorations. |
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