The Lematang Block in South Central Sumatra have an estimated total reserve of 330 BCF, the expected production life of 10 years is of substantial importance to MEDCO the fields operator. Wells in this field contain 32% CO2, 100-ppm H2S, BHP of 10,500-psi and BHT 408 degF and are therefore categorized as HPHT gas wells. The initial two wells were completed by the previous operator using 22Cr tubular material and 13 Chrome based material accessories. However, operational difficulties from material deterioration were identified. Optimization of the completions durability with the consideration of the economics of the completions was of paramount concern when selecting the materials and the completion tool designs.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractExploration and development of Heavy oil fields in Muglad Basin in Northern Africa started with conventional vertical wells and as time progressed this matured into drilling of horizontal and high angle wells.Typically drilling challenges in this area include drilling of very reactive shale's, shallow kick off depths and high build rates. Unconsolidated sandstones and interbedded shale's are sensitive to mud weight and are prone to lost circulation.First few horizontal wells were drilled with traditional technology of positive displacement motor with Silicate mud. Many of these wells faced hole cleaning challenges leading to pack off -excessive back reaming and stuck pipe incidences, uneven build rates via sliding in interbedded formation leading to high borehole tortuosity. It is significant to note that due to these difficulties one of the planned horizontal wells was sidetracked thrice after stuck pipe incidences and finally completed as a 30 deg deviated well with an AFE over run of 300%.

Most of the fields in Ecuador are considered "mature." Water injection is a well-known solution for mature fields. Water injection projects require a source of clean water. Traditionally, minimum specifications are achieved by surface treatment facilities. However, in the Ecuadorian Oriente Basin, the Hollin reservoir is an active aquifer with water meeting the requirements for use in waterflooding. But in other cases, water from production wells and from traditional surface facilities requires high investment costs because of associated facilities, chemical treatments, water production lines, and other requirements. A novel completion design has been developed. This proposed completion is called "modified dumpflooding" and represents a cost-effective solution for Ecuadorian mature fields. Dumpflooding is a modified version of dual concentric completion using most of its configuration pieces. It also takes advantage of extensive local experience in dual concentric completion design. Modified dumpflooding completion enables companies to use just one well for water production, injecting it into the depleted reservoir as a closed loop. Additionally, it helps to save costs in surface facilities by reducing human exposure to high pressure lines over large distances and eliminating operational expenditures for chemicals and equipment maintenance. Nodal analysis is foundational to helping companies understand how current design of waterflooding projects is behaving. It also provides a basis for mechanical configuration optimization to reduce bottlenecking points and improve completion performance.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractExploration and development of Heavy oil fields in Muglad Basin in Northern Africa started with conventional vertical wells and as time progressed this matured into drilling of horizontal and high angle wells.Typically drilling challenges in this area include drilling of very reactive shale's, shallow kick off depths and high build rates. Unconsolidated sandstones and interbedded shale's are sensitive to mud weight and are prone to lost circulation.First few horizontal wells were drilled with traditional technology of positive displacement motor with Silicate mud. Many of these wells faced hole cleaning challenges leading to pack off -excessive back reaming and stuck pipe incidences, uneven build rates via sliding in interbedded formation leading to high borehole tortuosity. It is significant to note that due to these difficulties one of the planned horizontal wells was sidetracked thrice after stuck pipe incidences and finally completed as a 30 deg deviated well with an AFE over run of 300%.