Optimization of Drilling &amp; Production Operations By Application of MPD Technique on Indian Offshore Basins - A Strategic Approach

A lot of wells were drilled in the fractured granite formation of Indonesian Jabung Block without any oil and gas show. However, a discovery was made by the utilization of under-balanced MPD technology. This paper gives a description of the technological process of the MPD technology and equipment used in the exploratory well Basement-1#. The 8-1/2in. hole section was drilled by application of MPD technology. The actual well depth is 8,269 ft, and the MPD hole section is between 4,993ft-8,269ft with footage of 3,276ft. The under-balanced drilling operation with managed pressure, tripping under managed pressure, displacement of weighted drilling fluid and overflow monitoring etc. had been successfully carried out during the MPD operation. Backpressure at wellhead was maintained in between 50-135psi. The abnormal downhole condition was monitored by little change of flow rate in and out of the well. Overflow was controlled in time and fluctuation of bottomhole pressure was decreased by use of accurate operation of the MPD equipment. A system of a synthetic based Gas-To-Liquid (GTL) drilling fluid was used to keep a low density as 7.4ppg since the formation pressure coefficient is around 1.04. The system kept good and stable performance with suspension and carrying capacity. The overall MPD process was effective without any problems. No losses occur, and non-production time was reduced. Success ignition was not sooner than drilling 30ft into the basement. 57 times of successful ignition were done in 300hrs of MPD operation. The longest continuous ignition reached 75hrs out of total 240hrs of ignition. The maximum total hydrocarbon reached 36.3% and revealed good hydrocarbon shows. Under-balanced managed pressure drilling could contribute to discovery of oil and gas reservoirs, make benefit to assessment of productivity of oil and gas wells. In addition, it increases rate of penetration, save overflow treatment time, and improve well control process.

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Application of UBD and MPD Improved Discovery of Fractured Granitic Basement Hydrocarbon Reservoirs

Chen

Wang

Chen

2017

Day 3 Wed, November 15, 2017

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Extensive discoveries of basement hydrocarbon reservoirs have been made in many places of fractured granite and carbonate basement in the world. Important hydrocarbon findings were achieved in fractured granitic basement in Chad and Indonesia by means of UBD and MPD technologies. The granitic basement in Chad and Indonesia featured with hydrostatic pore pressure gradient with narrow density windows and well developed fractures. The pore pressure coefficient of the basement of Chad was predicted in between 1.02-1.06, and an underbalanced drilling (UBD) technology with a micro-foam drilling fluid was used to make an attempt on reducing drilling fluid losses; the pore pressure coefficient of the basement of Indonesia was estimated to be 1.04, and an underbalanced managed pressure drilling (UB-MPD) technology with a synthetic based drilling fluid was utilized to avoid drilling fluid losses and in favor of hydrocarbon discovery. Different drilling technologies or modes received different results although drilling in same fractured granitic basement with similar pore pressure. Losses and kicks continued almost all the time during drilling, coring and wireline logging in some wells during UBD in Chad. Losses happened as soon as the rig pump started while overflow occurred no sooner than the rig pump stopped. However, the potential problem of losses and kicks was completely controlled by utilization of UB-MPD technology in Indonesia. No losses were found during underbalanced managed pressure drilling, tripping, connection, and circulation. Nevertheless, both basement hydrocarbon reservoirs in Chad and Indonesia have been obtained important discovery. Crude oil returned to the surface during UBD in Chad and abundant natural gas produced during UB-MPD in Indonesia. Both UBD and UB-MPD technologies are effective to gain the discovery of fractured granitic basement reservoirs. The underbalanced MPD technology, a precisely pressure controlled drilling system, is able to accurately control the annular pressure profile throughout the wellbore, therefore it could effectively achieve safe drilling in narrow density window and cut non-productive time. It is proved to be more effective and safer in drilling of fractured granitic basement.

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Optimization of Drilling & Production Operations By Application of MPD Technique on Indian Offshore Basins - A Strategic Approach

Cited by 4 publications

References 4 publications

An improved particle swarm algorithm to optimize PID neural network for pressure control strategy of managed pressure drilling

An improved particle swarm algorithm to optimize PID neural network for pressure control strategy of managed pressure drilling

Application of Under-Balanced MPD in Fractured Granite Formation of Indonesia

Application of UBD and MPD Improved Discovery of Fractured Granitic Basement Hydrocarbon Reservoirs

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