Arisandy, Mellinda (PETRONAS Carigali Indonesia Operations) | Mazied, Miftah (PETRONAS Carigali Indonesia Operations) | Putra, Bayu P (PETRONAS Carigali Indonesia Operations) | Yogapurana, Erik (PETRONAS Carigali Indonesia Operations) | B Mohd Idris, Jamin Jamil (PETRONAS Carigali Indonesia Operations) | Darmawan, Hendra I. (PETRONAS Carigali Kuala Lumpur)
This paper describes geochemistry analysis, hydrocarbon charge and entrapment model for prolific "MA" Block in the West Natuna Basin. Even though the area is currently at a mature exploration stage, the behaviour of hydrocarbon distribution in the area is still poorly understood and the link between discovered hydrocarbon and possible kitchens is still unknown. This study is an attempt to understand hydrocarbon expulsion, charging and entrapment in "MA" Block to de-risk further exploration efforts.
Several localized inverted half-grabens were identified through seismic interpretation. Nearby wells were then selected in evaluating source rock quality and maturity. In order to determine hydrocarbon expulsion model, 1D-3D burial history and thermal maturity models were constructed using integration of source rock and fluids geochemistry, temperature, seismic, and well data. Hydrocarbon charge and entrapment models were then simulated using 3D basin modeling software and calibrated with existing proven accumulation to produce a risked understanding of hydrocarbon distribution in the study area.
This study suggests that the most possible source rocks are the Late Eocene and Oligocene shales of Lama Formation and Lower Gabus Formations. Both source rocks are indicated by type I & type III kerogen. Lama source rock was confined in the initial grabens and post mature in deep paleo-grabens. This study confirmed that charging is derived from four (4) kitchen areas: Anoa, Gajah, Kakap, and Kambing grabens. The oil samples from "MA" Block indicated lacustrine facies. Rock geochemistry analysis portrayed oil-prone and gas-prone source rock.
In general, hydrocarbon was migrated from the southeastern area (Kambing graben) and southwestern area (Gajah graben). Hydrocarbon was later on accumulated in the nearest structural entrapments (anticlines). In the deep grabens (Kakap and Kambing), the hydrocarbon expulsion was starting as early as 37 Ma and 31 Ma, respectively, while in shallow graben (Anoa) the expulsion was starting at 29 Ma. The earliest structural trap commenced at 21 Ma, aligned with the initial compressional regime that was affecting the West Natuna Basin. Notable accumulative erosion in Miocene was nearly 1000 m at inverted structures, by which partly removed regional seal and reduced reservoir effectiveness. Significant yet-to-find hydrocarbon is predicted to be concentrated in the Anoa, Kakap, and Northeast Kambing area.
Gunawan, Indra (ConocoPhillips) | Bailey, Mike (ConocoPhillips) | Huffman, Chad (ConocoPhillips) | Simancas, Ricardo Gómez (Schlumberger) | Sanchez, Mariano (Schlumberger) | Choudhary, Suresh (Schlumberger) | Samuel, Mathew (Schlumberger)
Loss of completion fluid during a completion or work over operation not only increases the chance of losing control of the well, but also can severely damage the formation. The best industry recognized method to stop fluid losses into the formation is to use mechanical fluid loss control devices. However, sometimes, the use of mechanical fluid loss control device is not applicable. Two examples where fluid loss control devices are not applicable are (1) Shoot and Pull Tubing Conveyed Perforating (TCP) before a gravel pack or a frac pack, and (2) Single trip perforating and gravel pack or frac pack completions. In these cases the use of fluid loss control pills is necessary. Traditional fluid loss control pills are associated with formation damage, clean up trips and annular pack plugging. This paper presents the application of a Viscoelastic Surfactant-based non-damaging lost circulation pill (VES-PILL) during the completion of sub-sea gas wells in the South China Sea for ConocoPhillips.
This novel solids-free fluidloss control pill was applied to insure well control after perforating and before frac packing. This paper describes the cases from the two wells of which one was completed as a single trip multi-zone frac and pack completion and the other as commingled stack frac packs. These commingled stack frac packs consisted of multi-zone frac packs and gravel pack on bottom and a conventional frac pack on top. Both single trip completions considerably exceeded the world record for the longest single trip gravel packed completion. In the first well, well control was achieved and the losses were controlled from 322 bph to 8 bph. In the second application, during a traditional shoot and pull, the losses were controlled from 60 bph to 0 bph. After completion, the wells were tested at 87 and 55 MMSCFD at 400 psi WHP, and were found to exceed pre-drilling production estimates by about 17-24%. This further confirms the non-damaging property of this VES-PILL.
Jangkar-1X was drilled in the first quarter of 1998 and discovered oil and gas in five reservoirs in the Lower Gabus and Pasir Formations. The Jangkar Field is located in the Kakap PSC (Indonesia) and is part of the Wrench Fault Trend which has yielded significant rewards to the Kakap PSC partners. The well was not tested but open hole log evaluation, down hole fluid samples and pressure data confirmed the presence of oil and gas in highly porous and permeable sands. In response to this success, a fast track development plan was formulated which resulted in a second well, Jangkar-2X being drilled, completed and placed on production as a sub-sea oil producer prior to the end of 1998. This fast track development was the result of a strategic decision to pre-purchase the long delivery items required for sub-sea tie-ins in anticipation of a least one successful exploration well in a multi-well drilling program. This paper reviews the basis for the decision to pre-order inventory and documents the strategy and development plan which resulted in this well being placed on production within ten months of the field being discovered as well as the technical and commercial results of the project.