Lv, Zuobin (Tianjin Branch of CNOOC Ltd.) | Gao, Hongli (Tianjin Branch of CNOOC Ltd.) | Cheng, Qi (Tianjin Branch of CNOOC Ltd.) | Cheng, Dayong (Tianjin Branch of CNOOC Ltd.) | Meng, Zhiqiang (Tianjin Branch of CNOOC Ltd.)
JZS is an offshore metamorphic rock buried hill oilfield. Both horizontal and vertical velocities of the oil field change very fast. The interval velocity of the buried hill stratum is twice that of the overlying strata, and the top surface of the buried hill fluctuates greatly with a maximum height difference of 300m. In the complex buried hill reservoir, since the current professional seismic software can not realize variable time-depth relationship in horizontal direction, which leads to the error of the trajectory form and position of the horizontal well in time domain, therefore the well trajectory in time domain is not matched with that in depth.
In this paper, a new practical trajectories matching method for buried hill horizontal wells in time domain and in depth is presented. First of all, we carried on the research on the theoretical form of horizontal well trajectory in buried hill in time domain. The research shows that the theoretical trajectory form of a horizontal well in buried hill is consistent with trend of the buried hill top surface morphology. On the basis of theoretical research, by establishing the pseudo time-depth relationship of horizontal well based on measure depth (MD) and seismic reflection two way time (TWT), we realized the accurate characterization of the trajectory form and position of a horizontal well in buried hill in time domain: (1)For normal horizontal well with no more than 90 degrees inclination angle, we can respectively establish the pseudo time-depth relationship of the horizontal well in buried hill segment and in upper segment, and then merge both time-depth relationship data into a whole; (2)For the complex horizontal well with well segment whose inclination angle is more than 90 degrees, we need firstly split the well trajectory into normal well segment and complex segment according to inclination angle, then establish the pseudo time-depth relationship in normal and complex well segments respectively. More specifically, we can split the trajectory into normal trajectory segment with the inclination angle no more than 90 degrees and complex trajectory segment with the inclination angle more than 90 degrees, for normal segment, we can establish pseudo time-depth relationship like the normal horizontal well described earlier, for complex trajectory segment, we need creatively invert the top and bottom of the complex segment to convert inclination angle of the segment to within 90 degrees, and then establish pseudo time-depth relationship of the inverted segment.
Through this method, we can obtain the accurate trajectory form and position of the horizontal well in time domain and it provides a basis for accurate geological modeling based on 3D seismic attributes constrains. The real reservoir performance of JZS buried oilfield in Bohai Bay in China has proved that the 3D geological model based on the new time-depth relationship (MD&TWT) of the horizontal wells is closer to the actual reservoir.
The International Petroleum Technology Conference (IPTC) will be held from 26-28 March 2019 in Beijing, China at the Beijing International Convention Center. Returning to Beijing for the second time, this 11th edition of IPTC is hosted by China National Petroleum Corporation (CNPC) and co-hosted by Saudi Aramco.
According to the latest annual survey from industry technical advisor DNV-GL, digitalization is a strong No. 1 in the top ten research and development (R&D) priorities for oil and gas investments in 2019, and challenges have shifted from barriers of adoption to those related to increasing adoption. Forty-five percent of survey respondents said they would invest in digitalization this year—more than twice the 21% who said they would invest in the second-ranked priority, subsea technology. Thirty-six percent of senior oil and gas professionals and 60% of total respondents said they plan to increase investment this year, from R&D to full-scale implementation. The prevailing sentiment is that digitalization is crucial to providing the long-term efficiency and productivity gains the industry needs to maintain its competitiveness over the declining cost of renewable energy over the coming decades. Value Creation A 2017 report by the World Economic Forum says digitalization has the potential to create approximately $1.6 trillion of value for oil and gas firms.
Mozambique LNG1, a sales entity jointly owned by co-venturers in the Mozambique Offshore Area 1, has signed a sale and purchase agreement with CNOOC Gas and Power Singapore. Area 1 operator Anadarko said the agreement covers a supply of 1.5 mtpa over a 13-year term. Mozambique LNG will be the country’s first onshore LNG development. The facility will be equipped with two LNG trains with a total nameplate capacity of 12.88 mtpa to support the development of the Golfinho/Atum fields, which are located entirely within Offshore Area 1. Approximately 75 Tcf of recoverable natural gas has been discovered in Offshore Area 1, the equivalent of 12 billion bbl of oil.
The Chinese National Offshore Oil Corporaiton (CNOOC) has discovered a gas and condensate reservoir at the state-owned company’s Gelngorm prospect in the UK North Sea. The resource, located 118 miles east of Aberdeen, is estimated to hold close to 250 million bbl BOE. CNOOC tapped the reservoir in a water depth of 282 ft with a jackup rig. Total depth of the exploration well was just over 16,500 ft and gas and condensate pay zones were found with a thickness of 123 ft. The company had previously tried and failed to drill two prospect wells in 2017.
A bulk of near-term output will come domestically, but the subsidiary of state-owned China National Offshore Oil Corporation is leaning on its international projects to boost production longer-term. The company said it expects to produce 1.33 million BOE/D in 2019, an increase of 2% from its 2018 average, with domestic output accounting for 67% of this year’s production. The ExxonMobil-operated Guyana consortium has tallied 10 discoveries to date. CNOOC expects six new projects to come on stream this year. The four other projects are the Shell-operated Appomattox project in the US gulf and CNOOC’s Bozhong 34-9 oil field, Caofeidian 11-1/11-6 comprehensive adjustment project, and Wenchang 13-2 comprehensive adjustment project off China.
China is making steady progress in its shale gas activity, but a full-fledged boom is not on the horizon. China National Petroleum Company (CNPC) reported that shale gas production from its Sichuan Basin project increased by 40% between 2017 and 2018. Total gas output was pegged at 4.27 billion cubic meters (bcm), with daily output amounting to 20 million cubic meters (mcm). The figures are record highs, the company said. The daily production of 20 mcm is equivalent to about 0.7 Bcf/D.
China National Offshore Oil Corporation (CNOOC) has signed strategic cooperation agreements with nine international firms for two offshore areas in the Pearl River Mouth Basin off China. State-owned CNOOC said the agreements—which include Chevron, ConocoPhillips, Equinor, Husky, KUFPEC, Roc Oil, Shell, SK Innovation, and Total—are a first step in establishing what could be long-term cooperation on exploration and development of offshore Areas A and B. Each international firm has existing upstream operations in China. The 15,300-sq-km Area A lies in 80–120 m of water. Firms are open to explore its deep layers below the Paleogene Enping formation. The 48,700-sq-km Area B lies in 500–3,000 m of water.
Bian, Li’en (China National Offshore Oil Corporation (CNOOC) Ltd. Tianjin Branch) | Zhang, Jingsi (China National Offshore Oil Corporation (CNOOC) Ltd. Tianjin Branch) | Xu, Jialiang (China National Offshore Oil Corporation (CNOOC) Ltd. Tianjin Branch) | Yang, Wei (China National Offshore Oil Corporation (CNOOC) Ltd. Tianjin Branch) | Yu, Qian (China National Offshore Oil Corporation (CNOOC) Ltd. Tianjin Branch)
A good time-depth projection method plays an important role in improving the accuracy of depth prediction. When designing a new well, we need a time-depth relationship to predict the depth of the target layer and then design the well trajectory. The traditional approach is to directly use the time-depth relationship of adjacent well. However, as the target reservoir becomes more and more complex, the lateral change of the formation velocity is more and more large. In this case, the traditional approach is difficult to meet the research needs. This study proposed a new high precision time-depth projection method, which firstly establishes a high precision space-varying velocity model under the constraint of geological structure, then extracts the average velocity at each point of the well trajectory, and finally creates a high precision time-depth relationship based on MD (Measured Depth) of well trajectory which is different from the traditional time-depth relationship based on TVD (True Vertical Depth). The application result of real seismic data demonstrates the effectiveness of our method.
Presentation Date: Monday, October 15, 2018
Start Time: 1:50:00 PM
Location: 210A (Anaheim Convention Center)
Presentation Type: Oral