fax 01-972-952-9435. AbstractExtended reach wells drilled from the Goodwyn Alpha platform are highly aggressive and have been drilled with a variety of invert-emulsion mud systems. Historically, mud system selection for these wells was based on compliance to environmental regulations and satisfaction of technical criteria. In order to take a more proactive approach to mud system selection and to raise environmental standards to new levels, an initiative was undertaken to replace the environmentally acceptable, and technically competent mud system being used on Goodwyn with a new ester-based system. Ester-based mud systems are considered the "systemof-choice" in terms of environmental acceptability and possess inherent lubricating qualities for torque and drag reduction. This paper describes the development process and 4 successful field applications of the new ester-based mud system. A new ester, which exhibits the lowest kinematic viscosity of commercially available esters, was identified and selected for use. New and innovative technologies were introduced in the laboratory development and field applications to address barite sag, hole cleaning efficiency and hydrolytic stability.The system development and field testing processes were enhanced by daily communication with the development teams in Aberdeen, Houston and Perth. Down-hole friction factors were significantly lower than modeled predictions. Barite sag problems encountered on previous wells were eliminated, and hole cleaning efficiency was optimized.

Karachaganak Petroleum Operating B.V. (KPO) has implemented waste management process that maximizes waste reduction and waste reuse. Minimizing environmental impact was also a primary focus. This process incorporates waste minimization / segregation, oily water treatment, oil-based mud (OBM) drilled cuttings treatment and recycling of drilling muds and brines. KPO is now completing the central treatment site where it has deployed new equipment and which places it at the top of the international ladder as far as recycling, treatment and safe disposal of drilling fluids and drilling wastes are concerned. In arriving at this milestone KPO completed a 'Best Available Techniques' (BAT) review of drilling waste which is based on a review of worldwide handling and disposal techniques. This paper describes the current waste management practices established by KPO and the strategies identified by KPO for the final end point for the drilling wastes at the Karachaganak field in north-western part of the Republic of Kazakhstan.

GWA13 was the last well during Phase 1 of the development of the Goodwyn field and was drilled to a total depth of 8420m (27620') AHD with a horizontal step out of 7372m (24190') at a TVD of 2866m (9400'). The paper describes the planning processes before spud, and the equipment, techniques and directional control used during the drilling phase. Lessons that can be applied to both our own and other operations will be listed. The team approach to the drilling of Goodwyn wells will be emphasised and the risk assessment measures used both in the office and on the rig will be detailed. P. 271