Abstract

Atlantic Richfield Indonesia, Inc., brought five of seven platforms of the BIMA Field on stream in December, 1986. At the time of writing this paper, two additional platforms were being started up. Forty eight wells were drilled from the seven platforms, including sixteen horizontal (90) and high angle (85) wells drilled through the productive zone. All of the wells in the field were equipped with electric submersible pumps.

The early phase of the high angle well program was the subject of a paper presented to the 15th Annual Indonesian Petroleum Association in October, 1986. This update describes the transition from the original high angle well design to a horizontal well configuration and the use of downhole steering and directional control techniques to accomplish productive zone extended reach penetration lengths of up to 2173' with only a 19' TVD variation.

This paper also describes how measurement while drilling (MWD) technology was employed to obtain well directional and lithological data and also how MWD logs replaced drill pipe conveyed logging tools. The costs to drill and complete BIMA extended reach wells are shown to compare favorably with standard deviated holes.

Operating characteristics and problems encountered in the course of producing wells in the high angle and horizontal environment at BIMA are discussed. Early indications from production data analysis verify that high angle wells exhibit a reduced drawdown, as expected, meaning that reservoir management techniques to control water and gas coning can be applied without sacrificing oil rate.

Completions are described which illustrate how pump installations and wireline activities are limited to the upper sections of the high angle holes. Also described are techniques which will use novel workover engineering approaches in an attempt to control excessive water and gas influx in horizontal wells.

High angle wells have proven to be an economically practical approach in a complex reservoir such as the Batu Raja limestone in the BIMA Field. Atlantic Richfield Indonesia, Inc., has led the way in successfully drilling and operating these long reach wells in the Offshore N.W. Java contract area.

Introduction

The development drilling phase of the overall BIMA Field project resulted in an evolutionary series of changes to the original high angle drilling plan. These changes were based upon the learned experiences of several successful high angle (85 +/−) holes drilled in the field. Drilling practices employed during the final phase of the high angle well development drilling program incorporated a high confidence level in planning and drilling long (up to 2173' MD at 90), horizontal drainholes through the thin (average 35' TVD thick productive zone; top is at -2550'), loosely consolidated Batu Raja limestone.

What began as a bold plan to drill 85 degrees +/− angle wellbores through the Batu Raja limestone became a series of mechanical successes in drilling 90 holes using conventional drilling technology. At the completion of the BIMA development drilling program, Atlantic Richfield Indonesia, Inc., had succeeded in drilling over 18,200' of horizontal hole in eleven wells and 4200' of hole at angles from 85 to 90 in five wells.

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