MEMORANDUM

TO: Lisa Biddle, U.S. EPA

Karen Milam, U.S. EPA

FROM: Brent Ruminski, ERG

DATE: June 6, 2016

SUBJECT: Analysis of DI Desktop® (DCN SGE01180)

This memorandum describes ERG’s analysis of Drillinginfo’s (DI) Desktop® Well File 

Database that ERG used to supplement other analyses for the Technical Development Document 

for Effluent Limitations Guidelines and Standards for Oil and Gas Extraction (TDD) (DCN 

SGE01188). Specifically, this memorandum focuses on how ERG developed a database of active 

unconventional oil and gas (UOG) wells (DI Desktop® Development Database, DCN 

SGE01180.A01) from Drillinginfo’s nationwide database of all oil and gas wells. Table 1 lists 

the relevant TDD tables and/or figures and the TDD analyses supported by the DI Desktop®

Development database. TDD tables and figures not listed in Table 1 either did not require 

calculations and/or analyses by ERG or are described in separate, supporting memoranda. The 

Crosswalk Memorandum between Proposed and Final Technical Development Document for 

Effluent Limitations Guidelines and Standards for Oil and Gas Extraction: Tables and Figures

(DCN SGE01334) contains a crosswalk of all tables and figures in the TDD. Appendix F of the 

TDD contains the name of the relevant supporting memorandum for each TDD table and figure, 

where applicable. This memorandum is organized into the following sections:

 Section 0 provides background information about the DI Desktop® database and 

the purpose of this analysis.

 Section 2.0 discusses how ERG created the DI Desktop® Development database

which is used to create a subset of the DI Desktop® database containing only

active oil and gas wells and flag those that are drilled into UOG formations.

 Section 3.0 summarizes the results of the DI Desktop® database analysis and how 

they compare to literature.

 Section 4.0 describes ERG’s quality assurance procedures.

 Section 5.0 lists the references used for this analysis.

For those figures/tables ERG generated specifically for this memorandum, the underlying 

data and analysis are contained in: 

 Attachment 1 – DI Desktop® Development Database (DCN SGE01180.A01)

For the tables/figures explained in more detail in this memorandum, Table 1 provides the 

TDD chapter, memorandum section, and attachment information. 
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Table 1. Other UOG Analyses Supported by this Memorandum

TDD 

Chapter Supporting Analysis

TDD Table or 

Figure Number

Supporting Analysis 

DCN

B UOG Potential by Resource Type as of January 1, 2013 Table B-3

a SGE01179.A02

C

DI Desktop® Long-term Produced Water Rates Table C-8 & C-9

b SGE01184.A02 and A03

FracFocus® Fracturing Fluid Volumes Table C-7 & C-9

b SGE01184.A04 and A05

New Mexico Flowback Recovery Table C-7 & C-9

b SGE01184.A07

Wyoming Flowback Recovery Table C-7 & C-9

b SGE01184.A09

Niobrara Flowback Recovery Table C-7 & C-9

b SGE01184.A11

a— Methodology used to generate this table is explained in ERG’s memorandum titled Data Compilation 

Memorandum for the Technical Development Document (TDD) for Effluent Limitations Guidelines and Standards 

for Oil and Gas Extraction – DCN SGE01179.

b— Methodologies used to generate these tables are explained in ERG’s memorandum titled Unconventional Oil 

and Gas (UOG) Produced Water Volumes and Characterization Data Compilation – DCN SGE01184.

For definitions of common terms used throughout the TDD, the supporting memoranda, 

and memoranda attachments, please refer to the Glossary in the introduction of the TDD.

1.0 DI DESKTOP® DEVELOPMENT DATABASE BACKGROUND

Drillinginfo (DI) is an oil and gas research firm located in Austin, Texas. DI Desktop® is 

a comprehensive database generated by Drillinginfo that contains a record (i.e., row) for all oil 

and gas wells drilled in the United States.1 Drillinginfo uses oil and gas databases maintained by 

individual state oil and gas agencies to create the DI Desktop® database. For this analysis, ERG 

downloaded a version of the DI Desktop® database on March 30, 2015. For the most part, this

version of DI Desktop® reflects wells drilled as of 2014 but it varies by state. State-level 

information such as the oil and gas agency names, last production date2, production start date3, 

and update frequency (e.g., monthly, quarterly) is provided in Drillinginfo’s Data Coverage table 

(DCN SGE01171). The raw DI Desktop® database ERG used for this analysis is contained in the 

“DI Desktop Wells (SGE01170)” table of Attachment 1 (DCN SGE01180.A01) in addition to 

DCN SGE01170. 

Basic well data contained in DI Desktop® for each well includes: well API number4,

location, operator, and well trajectory. DI Desktop® also includes annual oil, gas, and produced 

water production per well. Table 2 provides the complete list of data fields in DI Desktop®. The 

fields ERG used either in this analysis or in other UOG TDD supporting analyses are marked 

with an asterisk. All other fields were not used by ERG.

 

1 The database is subject to restrictions on its use and dissemination. Based on the license agreement discussions, 

access to the raw data in the database is limited to ERG and EPA personnel only; although summary data developed 

using queries can be disseminated more widely. Wholesale “data dumps” cannot be disseminated electronically. All 

disseminations of such summary data, however, should cite Drillinginfo as the source of the information.

2 This is the date that the state last updated the data that Drillinginfo included in ERG’s version of the DI Desktop®

database downloaded on March 30, 2015.

3 First year that the state agency maintained records for oil and gas wells. 

4 An API number is a unique identifier assigned to each well drilled for oil and gas in the United States. 
Analysis of DI Desktop® Memorandum

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DI Desktop® includes records for wells that are no longer active (i.e., shut in), 

underground injection wells5that do not produce oil and/or gas, conventional oil and gas (COG) 

wells, CBM wells, and UOG wells. It does not, however, contain a field that indicates if wells 

are conventional or unconventional. Section 2.0 describes how ERG determined which active 

wells in the raw DI Desktop® database are drilled into UOG formations.

Table 2. Field Names and Descriptions in DI Desktop®

Field Name Description

ENTITY_ID* DI assigned ID unique to a given property. A well is referred to as a “property” in DI 

Desktop®.

API_NO* API assigned number of a well on the property.

PROPERTY_TYPE Property type (e.g., lease, unit, well, completion, other, unknown).

PRODUCTION_TYPE Production type (e.g., oil, gas, injection).

PROD_TYPE_CLASS*

Classification of production type into D&A (drilled and abandoned), gas, injection, 

O&G (oil and gas), oil, and other.

PROD_FLAG

Production flag to indicate whether the well should be producing liquids. This is 

“Yes” for “Gas,” “Oil,” and “O&G” production type classification.

LIQUID_PROD_TYPE

Liquid production type (i.e., unknown, condensate, or oil) based on the production 

type classification and well test data.

WELL_NAME Operator assigned well/lease name of the property.

FIELD Field name the property is reporting from.

CURR_OPER_NAME Current operator name.

SPUD_DATE* Date drilling commenced on property.

COMMON_OPER_NAME Corporate entity that is determined by DI to own the current operator.

LATITUDE_NAD27 Surface latitude the property is located in; for multi-well properties DI Desktop®

picked a well to designate the location of the property, in NAD27 format. 

LONGITUDE_NAD27 Surface longitude the property is located in; for multi-well properties DI Desktop®

picked a well to designate the location of the property, in NAD27 format.

LATITUDE_NAD83

Surface latitude the property is located in; for multi-well properties DI Desktop®

picked a well to designate the location of the property, in NAD83 format. 

LONGITUDE_NAD83

Surface longitude the property is located in; for multi-well properties DI Desktop®

picked a well to designate the location of the property, in NAD83 format. 

COUNTY County the property is located in.

FIPS_CODE Federal Information Processing Standard (FIPS) county code based on county or GIS 

analysis using latitude and longitude.

DISTRICT District within a given state the property is assigned.

STATE* State the property is located in.

EPA_REGION EPA region the property is located in.

OFFSHORE Offshore waters indicator.

RESERVOIR* Reservoir, formation, zone, or pool that the property is reported as producing from.

BASIN* The basin the property is located in.

FORMATION* Formation that the property is reported as producing from. 

 

5 For more information about underground injection wells, see ERG’s TDD supporting memorandum titled Analysis 

of Active Underground Injection for Disposal Wells - DCN SGE01187.
Analysis of DI Desktop® Memorandum

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Table 2. Field Names and Descriptions in DI Desktop®

Field Name Description

STATUS* Current status of the well (e.g., active, inactive, shut in).

TOTAL_DEPTH Total depth the well was drilled to.

PLUG_DATE Date the well was plugged. Note: for instances where duplicate API numbers were 

combined, the maximum value was selected.

COMPLETION_DATE* Most recent completion date of the well.

COMPLETION_YEAR* Year of the completion date.

Well Trajectory

This is the configuration of the wellbore. Options include: H – Horizontal; D –

Directional; V – Vertical; U – Unknown.

FIRST_PROD_DATE First date of reported production for the property. Note: for instances where duplicate 

API numbers were combined, the minimum value was selected.

LAST_PROD_DATE* Last date production was reported for the property.

LATITUDE_BOTM Bottom hole latitude of the property.

LONGITUDE_BOTM Bottom hole longitude of the property.

SumOfLIQ[xx] Annual oil production in barrels. A separate column is provided for each year from 

2000 (i.e., “SUMOFLIQ00”) through 2014 (i.e., “SUMOFLIQ14”).

SumOfGAS[xx] Annual Gas production in thousand cubic feet. A separate column is provided for 

each year from 2000 (i.e., “SUMOFGAS00”) through 2014 (i.e., “SUMOFGAS14”).

SumOfWTR[xx]* Annual produced water production in barrels. A separate column is provided for each 

year from 2000 (i.e., “SUMOFWTR00”) through 2014 (i.e., “SUMOFWTR14”).

PROD[xx]_FLAG Yes/No flag indicating if oil and/or gas production was greater than zero for a given 

year. A separate column is provided for each year from 2000 (i.e., 

“PROD00_FLAG”) through 2014 (i.e., “PROD14_FLAG”).

ACTIVE_FLAG Yes/No flag indicating whether or not a well is active based on production.

ACTIVE_PROD_FLAG Yes/No flag indicating whether the entity (i.e., property) is active (using the 

ACTIVE_FLAG field) and had production in 2014 (using the PROD14_FLAG field).

2.0 DEVELOPMENT DATABASE METHODOLOGY

The following steps describe how ERG used the raw DI Desktop® database to make a list 

of active oil and gas extraction wells drilled into UOG formations. These steps outline the 

queries in Attachment 1 (DCN SGE01180.A01).

Step 1 – Create Active Oil and Gas Wells Table 

ERG used query 100 in Attachment 1 to create a list of active oil and gas extraction 

wells. This query checks each well record in the raw DI Desktop® database (i.e., the table “DI 

Desktop Wells (SGE01170)” in Attachment 1) against the two sets of criteria listed below to 

identify oil and gas wells that are active. It makes a new table called “Active Oil and Gas Wells” 

in Attachment 1 that contains the final list of active oil and gas wells. 

1. Query 100 only includes wells that are designated as “oil”, “gas”, or “O&G” in 

the PROD_TYPE_CLASS field. This removes wells that are classified as 

injection wells, carbon storage wells, water wells, etc.
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2. For all states, ERG considered active wells to be those that produced oil, gas, 

and/or produced water during the year that the data was last updated by 

Drillinginfo.

6 Because each state updates their data at different times, ERG used 

different dates for each state to complete this step.7 The most recent production 

date for each state is provided in Drillinginfo’s Data Coverage table (DCN 

SGE01171). 

Step 2 – Create Consolidated Formation Crosswalk

DI Desktop® does not identify wells as unconventional or conventional. However, it 

identifies the basin, reservoir, and formation in which the well is completed. ERG used this 

information to identify UOG wells. However, because these fields include inconsistent naming 

conventions and spelling errors, ERG created a comprehensive crosswalk between the basin, 

reservoir, and formation reported in DI Desktop®; consolidated UOG formation names

(developed by ERG); and applicable resource type. Table 3 provides examples of these 

consolidations. The full crosswalk contains over 46,000 combinations and is in the table called 

“Formation Consolidation Crosswalk” in Attachment 1 (DCN SGE01180.A01). Section 3.0

discusses data quality related to this crosswalk.

To assign consolidated UOG formation names, ERG searched the basin, reservoir, and/or 

formation names reported in DI Desktop® for the basin and UOG formation names listed in 

Table 9.3 of EIA’s Assumptions to the 2015 Annual Energy Outlook report (DCN SGE01190), 

which is a complete list of UOG formations in the U.S. known by EIA as of the end of 2013. To 

assign resource type, ERG determined whether the formation is listed on EIA’s map of shale 

formations (DCN SGE01191) or EIA’s map of tight formations (DCN SGE00155). ERG used 

other references to supplement the EIA report as needed to identify UOG formation names

and/or applicable resource type. The DOCUMENTATION field in the consolidated formation 

crosswalk contains the DCN(s) for the reference(s) ERG used to identify each UOG formation.

Table 3. Formation Consolidation Examples

Reported Basin in DI 

Desktop®

Reported Reservoir in DI 

Desktop®

Reported Formation in 

DI Desktop®

Consolidated 

UOG 

Formation

(assigned by 

ERG)

Resource 

Type 

(assigned 

by ERG)

TX & LA GULF COAST EAGLE FORD-1 EAGLEFORD-1 Eagle Ford shale

TX & LA GULF COAST [blank] EAGLE FORD Eagle Ford shale

TX & LA GULF COAST EAGLE FORD [blank] Eagle Ford shale

ANADARKO GRANITE WASH GRANITE WASH Granite Wash tight

 

6 This is the date that the state last updated the data that Drillinginfo included in ERG’s version of the DI Desktop® 

database downloaded on March 30, 2015. 

7 For KY and TN, the data were last updated in December 2012. For MD, NY, OH, OR, VA, and WV the data were 

last updated in December 2013. For MO, the data were last updated in April 2014. For AL, the data were last 

updated in September 2014. For MI and NV, the data were last updated in October 2014. For AR, CA, MS, MT, and 

OK, the data were last updated in November 2014. For AZ, CO, KS, LA, NE, NM, PA, SD, UT, and WY, the data 

were last updated in December 2014. For AK, FL, ND, and TX, the data were last updated in January 2015 (DCN 

SGE01171).
Analysis of DI Desktop® Memorandum

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Table 3. Formation Consolidation Examples

Reported Basin in DI 

Desktop®

Reported Reservoir in DI 

Desktop®

Reported Formation in 

DI Desktop®

Consolidated 

UOG 

Formation

(assigned by 

ERG)

Resource 

Type 

(assigned 

by ERG)

ANADARKO (N GRANITE WASH CONS Granite Wash tight

ANADARKO GRANITE WASH GRANITE WASH -C- Granite Wash tight

EAST TEXAS HA HA Haynesville shale

EAST TEXAS HAYNESVILLE SH HAYNESVILLE SH Haynesville shale

EAST TEXAS HAYNESVILLE HAYNESVILLE Haynesville shale

Step 3 – Update Active Oil and Gas Table (Query 200)

Lastly, ERG used Query 200 in Attachment 1 (DCN SGE01180.A01) to update the 

“Active Oil and Gas Wells” table with consolidated UOG formation names and resource type. 

This query updates the RESOURCE_TYPE and CONSOLIDATED FORMATION fields in the 

“Active Oil and Gas Wells” table by cross referencing the reported basin and formation

combination against the “Consolidated Formation Crosswalk” table ERG created in Step 2.

3.0 DI DESKTOP® ANALYSIS RESULTS

Table 4 shows the total number of active wells identified by ERG in the DI Desktop®

database by resource type and well trajectory. ERG generated the results in Table 4 using query 

300 in Attachment 1 (DCN SGE01180.A01).

8 For comparison, the total number of active oil and 

gas wells reported by EIA for 2011 (DCN SGE01176) is included in Table 4. Wells that ERG 

did not identify as UOG are included in the “COG and CBM” category. 

The total number of UOG wells that were active in 2014 may have been higher than the 

number ERG estimated. This is primarily because the FORMATION field for over 140,000

active oil and gas wells was reported as “N/A”, “0”, “N”, or blank such that ERG could not 

identify a common formation name and could not determine if the well was in a conventional or 

unconventional formation (see Step 3 in Section 2.0).

Table 4. Summary of Active Oil and Gas Extraction Wells 

Resource Type

Identified by ERG in DI Desktop® by Well Trajectory 

(2014)

a

Reported by 

EIA (2011) H b,c orizontal Directional Vertical Unknown Total

UOG: Tight 11,175 12,565 82,954 36,208 142,902 NR

UOG: Shale 56,801 1,836 15,877 17,755 92,269 NR

COG and CBM 24,936 35,607 577,379 246,005 883,927 NR

Total 92,912 50,008 676,210 299,968 1,119,098 1,040,000

 

8 Query 300 is a crosstab query that counts the number of wells in the “Active Oil and Gas Wells” table by well 

trajectory and resource type.
Analysis of DI Desktop® Memorandum

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a— For the most part, this version of DI Desktop® reflects wells drilled as of 2014 but it varies by state (see DCN 

SGE01171 for state-by-state dates).

b—Source for EIA well counts: DCN SGE01176.

c—ERG was unable to identify a more recent national level count of active oil and gas wells.

4.0 QUALITY CONTROL PROCEDURES

All of the analyses presented in this memorandum adhered to the Environmental 

Engineering Support for Clean Water Regulations Programmatic Quality Assurance Project 

Plan (PQAPP) (DCN SGE00957) and the Unconventional Oil and Gas (UOG) Supplemental 

Quality Assurance Project Plan (SQAPP) (DCN SGE00958), including collecting, evaluating, 

and analyzing existing data and information.

Specifically, ERG used the procedures described in Section 4 of the PQAPP to gather and 

manage existing data in support of the UOG rulemaking. ERG staff entered reference 

information for relevant sources into the UOG Literature Review database. The ERG index 

keeper reviewed all reference information, assigned each reference a Document Control Number 

(DCN), imported the reference information into the UOG Project File Index database, and saved 

referenced files in the Electronic Project File folder.

ERG also used the procedures described in Section 3 of the SQAPP when collecting 

existing data for use in the UOG rulemaking. ERG used a combination of sources, including 

reports, papers, and online databases from state regulatory agencies such as departments (e.g., oil 

and gas commissions). As shown in Table 5 in this memorandum, ERG assigned a source flag 

(A, B, C or D) to all references used in these analyses. ERG did not use any Source Flag C or D 

references in this analysis. ERG defines each source flag as follows: 

 Source Flag A - Journal articles and documents prepared by or for a government 

agency (e.g., site visit reports, industry meeting notes); 

 Source Flag B - Documents prepared by a verified source9that include citation 

information (e.g., operator reports, vendor documents, conference presentations, 

university publications); 

 Source Flag C - Documents prepared by a verified source that do not include citation 

information (e.g., operator reports, vendor documents, conference presentations); and 

 Source Flag D - Documents prepared by a source that could not be verified and that 

do not include citation information.

EPA and ERG followed the procedures described in Section 7.0 of the PQAPP to 

generate, evaluate, and analyze data. ERG conducted the following QA checks during the 

analyses:

 ERG created the Microsoft Access database provided in Attachment 1 and 

performed a 100 percent check of all queries, and documented these in internal 

versions of the databases.

 

9 ERG considered sources as “verified” if we were able to find information about the author outside of the reference 

document. ERG primarily verified information by looking for company/organization websites that confirmed the 

author’s affiliation with the UOG industry.
Analysis of DI Desktop® Memorandum

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 ERG created two crosswalks in the Microsoft Access database provided in 

Attachment 1 and performed a 20 percent check of all records in them.

 ERG had a senior staff member familiar with ELGs and the UOG rulemaking 

review all analyses.

5.0 REFERENCES

Table 5 provides DCNs, citations, and source flags for references used in this analysis. 

The references in Table 5 are sorted numerically by DCN.

Table 5. References

DCN Source Citation 

Source 

Flaga

SGE00155 U.S. Energy Information Administration (EIA). 2010. Tight Sands Gas Plays, 

Lower 48 States. Prepared by EIA Office of Oil and Gas. (June).

A

SGE00330 Energy Information Administration (EIA). 2011. Review of Emerging 

Resources: U.S. Shale Gas and Shale Oil Plays.

A

SGE00442.A06 Murray, Kyle E. 2013. Examining Water Production Volumes and Produced 

Water Quality in the Mississippi Lime to Develop Appropriate Management 

Strategies. Mississippi Lime Production and Produced Water.

B

SGE00957 Eastern Research Group, Inc. 2014. Environmental Engineering Support for 

Clean Water Regulations Programmatic Quality Assurance Project Plan 

(PQAPP).

A

SGE00958 Eastern Research Group, Inc. 2014. Unconventional Oil and Gas (UOG) 

Supplemental Quality Assurance Project Plan (SQAPP).

A

SGE00991 United States Geological Survey. 2008. Assessment of Undiscovered Oil and 

Gas Resources of the Permian Basin Province of West Texas and Southeast 

New Mexico, 2007.

A

SGE01023 Office of Governor Dennis Gaugaard. 2012. South Dakota Oil and Gas 

Development/Preparedness Executive Branch Work Groups: Summary of 

Findings. (September).

A

SGE01170 DrillingInfo. 2015. DI Desktop® March 2015 Download_CBI. B

SGE01171 Drillinginfo. 2015. HPDI Data Coverage. (March 31). B

SGE01176 DrillingInfo, Inc. 2015. HPDI Data Coverage. (March 30). A

SGE01187 ERG. 2016. Analysis of Active Underground Injection for Disposal Wells. A

SGE01190 U.S. Energy Information Administration. 2015. Assumptions to the Annual 

Energy Outlook 2015.

A

SGE01191 U.S. Energy Information Administration. 2015. Lower 48 States Shale Plays. 

Prepared by EIA Office of Oil and Gas. (April).

A

SGE01334 ERG. 2016. Memorandum Providing a Crosswalk between Tables and 

Figures in the Proposed and Final Technical Development Document for 

Effluent Limitations Guidelines and Standards for Oil and Gas Extraction.

A

a—Source Flag A—Journal articles and documents prepared by or for a government agency (e.g., site visit 

reports, industry meeting notes).

Source Flag B—Documents prepared by a verified source that include citation information (e.g., operator 

reports, vendor documents, university publications).

Source Flag C—Documents prepared by a verified source that do not include citation information (e.g., 

operator reports, vendor documents, conference presentations); and 
Analysis of DI Desktop® Memorandum

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Source Flag D—Documents prepared by a source that could not be verified and that do not include citation 

information.
Analysis of DI Desktop® Memorandum

October 9, 2015

Page 10

ATTACHMENT 1: DI DESKTOP® DEVELOPMENT DATABASE (DCN SGE01180.A01)