Risk Cost Analysis Between Pilot Hole with Geosteering Using Decision Tree Analysis

EasyChair Preprint 6579

Abstract

In implementing horizontal drilling, one of the challenges is the risk of uncertainty formation that causes difficulties in performing well placement. Thus, in planning and budgeting horizontal well drilling activities, a deterministic approach is needed. The determination can be done using a decision picker tool that depends on the decision tree analysis's initial capital value (DTA).  The aim is to create a predicted model with the value of a target variable by knowing every decision option.

In developing the X-10 horizontal well, the DW field, Malaysia selected two mitigation options using a pilot hole or geosteering to conduct well placement. The option is according to the uncertainty depth condition from the offset well data. There is no denying that there is still a risk of drilling trajectory exit from the target zone when entering the lateral section (called miss landing) in implementing one of these mitigations. This incident occurred at the X-07 well section 12-1/4", where drilling was out too far from the formation target. So, to continue, drilling must be done sidetrack and requiring additional time and cost. Therefore, it takes analysis that calculates risk-based, efficiency ratio, and expected monetary value (EMV).  To be able to recommend which decisions are the best and have the most negligible risk costs.

Previously, drilling operational timing and costs have been calculated in each mitigation. Hence, to continue the proper planning of the well, this paper will decide based on calculating existing risk costs by using DTA. By calculating each possibility's expected value (EV), the total price of risk costs is obtained in each mitigation. The geosteering has a lower total assessment cost of 5.666.139,55 USD, against a pilot hole of 7,650,501.42 USD. Geosteering can reduce the potential risk by 1,984,361.87 USD with an efficiency of 25.94% for the 12-1/4" section in the X-10 well.

Keyphrases: Decision Tree, Geosteering, Pilot hole, cost efficiency, horizontal well

@booklet{EasyChair:6579,
  author    = {Mulia Ginting and Rizki Akbar and Raisha Ummaria},
  title     = {Risk Cost Analysis Between Pilot Hole with Geosteering Using Decision Tree Analysis},
  howpublished = {EasyChair Preprint 6579},
  year      = {EasyChair, 2021}}