Importance of Multi-Domain Integration in Selection of a Proper Landing Point for Unconventional Horizontal Drilling and Completions
Authors: Narasimhan Santhosh , Nguyen Kim Long , Verma Naveen , Fahmy Mahmoud Fawzy , Al-Morakhi Rasha , Jumah Meshael , Quttainah Riyad , Iqbal Javed , Hayes Dawn , Rowe Harry , Arrington Sean 
Published: September 2022

Historically, understanding and selecting a successful landing point candidate for horizontal drilling and fracturing was mostly performed based on a single-domain perspective or purely based on geoscience data sets. On the other hand, this paper proposes an unconventional multi-domain integration for shale oil and shale gas development for successful drilling and completions. In heterogeneous formations where organic-rich rocks are the source and reservoir, the geology and petrophysics along with engineering integration is a must for short- and long-term production and optimization. In this unconventional approach, petrophysical and 1D mechanical earth models were developed using triple combo (TCOM) and sonic by integrating in-situ core measurements to narrow down the uncertainty in the flow and mechanical properties. In the standard approach, landing points are mostly selected by looking for good petrophysical reservoir units with good porosity, good organics and low water saturation. However, these good petrophysical-rich rocks could be geomechanically highly stressed (both total and effective) and less brittle. Completion engineers mostly prefer to drill and frac low stress and brittle facies. This is because brittle rocks with proppant in the fractures can keep the fracs open for a longer time without getting into the embedment issues as a result of production. If embedment becomes an issue as a result of depletion in the highly stressed landed horizontal wells, then there is a possibility for significant drop in production sharply in short time. In this paper a few potential reservoir units are selected as landing points for horizontal drilling based on petrophysical derivatives followed by the geomechanical attributes of good brittle and low stress of the reservoir sections within the Najmah (NJW) and Sargelu (SRW) formations. For each landing point, frac modeling was performed to obtain height and length. Geometries from each landing point are different due to vertical geomechanical heterogeneity. These vertical stacking patterns for facies and properties combined with a certain completion design will determine the fracture propagation and pinch points vs. barriers. Generated frac heights from each landing point will be compared with petrophysics to understand the thickness of organic-rich intervals vs. water content. Based on the initial geometries from each landing point, completion optimization was performed by altering the rate vs. volume pumped to understand the variations in fracture height and length. This is to illustrate the completion vs. production cost economics based on single well modeling. Since Najmah (NJW) - Sargelu (SRW) organic-rich source reservoirs in Kuwait are in early appraisal phase, the data set lacks pressure and production history. Hence the validation of frac geometries is not discussed.