Liu, Han-lin (School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University) | Wang, Lei (School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University) | Chen, Gang (School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University)
Zhang, Feng (School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University) | Wang, Lei (School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University) | Yan, Fang (School of Naval Architecture, Ocean and Civil Engineering, Shanghai Jiao Tong University)
For monitoring hydraulic fracture (HF) in oil/gas fields the most reliable seismic method to avoid the adverse effect of strong surface noises is using downhole microseismic surveys . Nevertheless, downhole measurement is more expensive and limited by the availability of suitable boreholes in the vicinity of the hydro-fracture site.By all means seismic surveys conducted on land surface bear the largest flexibility and are more economic than downhole measurements. As a significant progress in hydro-fracture monitoring Duncan et al developed a surface monitoring system using seismic arrays centered at the hydro-fracture point. This monitoring method requires large-scale and prolonged operations; thus the cost-effectiveness is still less than ideal. In this paper we present a novel approach for land monitoring of hydro-fractures that uses only sparse seismic stations far from fracturing vehicles; and the total number of seismic stations is much less than previous approaches; so that the cost-effectiveness is significantly improved. With a small-scale seismic array on land surface we have monitored the hydro-fracture processes using a vector scanning technique for imaging hydro-fractures and determining rupture focal mechanisms. The applications of this technique to a synthetic data set based on numerical modeling and the real-world field data show that it is able to trace the tempo-spatial development of hydro-fractures even when the signal to noise ratio (S/N) is lower than 0.5. The vector scanning technique significantly shows the fracture imaging quality, and provides us a cost-effective approach for monitoring flow-enhancement hydro-fracture processes.
Wang, Lei (No. 6 Production Co. of PetroChina Daqing Oilfield Company Ltd.) | Wang, Yingwei (No. 4 Oil Production Co. of PetroChina Daqing Oilfield Co. Ltd.) | Pu, Hui (Energy & Environmental Research Center) | Zhang, Chengli (Northeast Petroleum University) | Yin, Daiyin (Daqing Petroleum Institute) | Wang, Liping (No. 6 Production Co. of PetroChina Daqing Oilfield Company Ltd.)
Taking PI1-2 oil-bearing formations of northeast block in Lamadian oilfield as an example, laboratory experiments of high-concentration polymer flooding in artificial five-spot flat-panel core model are conducted, the effect of polymer molecular weight, concentration, slug size on oil displacement effect are evaluated and the influence on injection pressure of those parameters are analyzed. At the same time, injection parameters, such as polymer molecular weight, concentration and slug size etc, are optimized combined with actual injection ability of high-concentration polymer flooding from the pilot site. The results show: high-concentration polymer flooding after polymer flooding can further improve recovery, in addition, episode recovery degree can be improved with the increase of concentration and high-concentration slug; the theory of similarity on injection-production differential pressure between laboratory flat model experiment and actual reservoir is put forward, and parameters information of injection pressure in real reservoir are obtained through upscaling the flat model; the optimized polymer injection parameters for the pilot site in Lamadian oilfield are molecular weight of 25 million, concentration of 3,500mg/L, slug size of 0.5 PV, and the recovery can be improved 8.47%OOIP through using those optimal parameters.
James, Richard Wayne (Exxon Mobil Corporation) | Pastusek, Paul E. (ExxonMobil Development Co.) | Kuhn, Gary R. (ExxonMobil Development Co.) | Andreev, Anton (Exxon Neftegas Limited) | Bailey, Jeffrey R. (ExxonMobil Upstream Research Co.) | Wang, Lei (ExxonMobil Upstream Research Co.)
Numerous performance enhancement initiatives were used by the operator for the Sakhalin I project in drilling and completing the world-class extended reach drilling (ERD) program at the Odoptu Field, Sakhalin Island, Russia. As a result of the drilling successes and favorable production performance, the initial seven-well ERD program was expanded to nine wells, including the world record OP-11 well. The operator's philosophy of relentless redesign to remove limiters from the drilling process resulted in significant performance improvements in all areas of drilling and completion operations. This paper provides details and results for many of the key performance initiatives used.
Operators are continually striving to drill longer, faster, and at lower costs while minimizing risks to provide maximum shareholder value. During the Odoptu ERD drilling program, a constant progression of performance improvement, time reduction, and dependability strategies were used. These optimization initiatives resulted in significant performance improvements for the project and numerous industry records.
The nine Odoptu ERD wells were drilled at a cost below the budgeted amount for the first seven wells. As a result of the initiatives employed, non-productive time (NPT) was reduced from an average of 21% on the first four wells to less than 3% on the last five. Aggressive shock and vibration mitigation efforts through bit redesign, bottomhole assembly (BHA) vibration analysis and operational optimizations resulted in record BHA runs. Wellbore instability issues were successfully mitigated through design and operational practices. Completion practices were high-graded and optimized and as a result, all completions in the long horizontal intervals were successfully placed using partial string rotation techniques.
Drilling ERD wells at the edge of industry experience in a cost effective and low-risk manner requires careful attention to detail and a commitment by the operator and contractors to continuously improve.
The Odoptu field is one of three fields Exxon Neftegas Limited (ENL) is developing off the coast of Sakhalin Island Russia as part of the Sakhalin I Project (Fig. 1). The climate is sub-arctic with temperatures lower than freezing over half of the year, and temperatures below -40°C. It is also at the northeastern edge of the Eurasian tectonic plate and is subject to significant earthquake activity, the most recent of which was 7.6 on the Richter scale experienced in 1995. Exxon Neftegas Limited (ENL), an ExxonMobil affiliate, is the operator of the Sakhalin I Consortium in partnership with SODECO of Japan, ONGC Videsh Ltd of India, Sakhalinmorneftegas-Shelf of Russia, and RN-Astra of Russia.